MAY 2011

U.S. Department of Justice
Office of Justice Programs
National Institute of Justice

Special

RepoRt

Study of Deaths Following Electro Muscular Disruption
www.nij.gov

Office of Justice Programs
Innovation • Partnerships • Safer Neighborhoods
www.ojp.usdoj.gov

U.S. Department of Justice
Office of Justice Programs
810 Seventh Street N.W.
Washington, DC 20531
Eric H. Holder, Jr.
Attorney General
Laurie O. Robinson
Assistant Attorney General
John H. Laub
Director, National Institute of Justice

This and other publications and products of the National Institute
of Justice can be found at:
National Institute of Justice
www.nij.gov

Office of Justice Programs
Innovation • Partnerships • Safer Neighborhoods
www.ojp.usdoj.gov

MAY 2011

Study of Deaths Following Electro
Muscular Disruption

NCJ 233432

John H. Laub
Director, National Institute of Justice

Findings and conclusions of the research reported here are those of the authors and do not
reflect the official position and policies of their respective organizations or the U. S. Department
of Justice.
The products, manufacturers and organizations discussed in this document are presented for
informational purposes only and do not constitute product approval or endorsement by the U. S.
Department of Justice.
The National Institute of Justice is a component of the Office of Justice Programs, which also
includes the Bureau of Justice Assistance; the Bureau of Justice Statistics; the Community
Capacity Development Office; the Office for Victims of Crime; the Office of Juvenile Justice and
Delinquency Prevention; and the Office of Sex Offender Sentencing, Monitoring, Apprehending,
Registering, and Tracking (SMART).

Study of Deaths Following Electro Muscular Disruption
ACKNOWLEDGMENTS
The National Institute of Justice gratefully acknowledges the following individuals. Their information, insight and
knowledge benefited the development of this report.
Larry Amerson
Sheriff, Calhoun County, Ala.

David Hammel
Detective Sergeant (Ret), Maryland State Police

Albert Arena
Project Manager
International Association of Chiefs of Police

Joseph Kocab
Chief, Brooklyn Heights,
Ohio, Police Department

Laura Beck
Corporal, Maryland State Police

Mark Marshall
Chief, Smithfield,

Va., Police Department


Deborah Boelling
Assistant Director
St. Louis, Mo., Police Academy

James Martyn
Lieutenant, Maryland State Police

John Branham
Sergeant, Maryland State Police

James McMahon
Deputy Executive Director
International Association of Chiefs of Police

William L. Brewer
Captain, Birmingham, Ala.., Police Department

Jeffrey B. Miller
Colonel, Superintendent (Ret),
Pennsylvania State Police

Vernon Busby
Officer, Phoenix, Ariz., Police Department

Peter Modafferi
Chief of Detectives, Rockland County,
N.Y., District Attorney’s Office

John Cook
Detective Sergeant, Maryland State Police
Dan Cornwell
Captain, Maryland State Police

Karen Montejo
Chief, Miami-Dade,
Fla., Police Department

Dawn Diedrich
Deputy Director of Legal Services
Georgia Bureau of Investigation

Dan Rosenblatt
Executive Director
International Association of Chiefs of Police

Lisa Erazo
Project Coordinator
International Association of Chiefs of Police

Michael A. Spochart
Lieutenant, U.S. Capitol Police

John Firman
Director
International Association of Chiefs of Police Research
Center

Sabrina Tapp-Harper
Lieutenant, Baltimore,
Md., Police Department
Douglas Ventre
Lieutenant, Cincinnati, Ohio, Police Department

Alan Goldberg
Captain, Montgomery County,
Md., Police Department

Otis Whitaker
Sergeant, Maryland State Police

John Grant
Senior Program Manager
International Association of Chiefs of Police

Ray Wojcik
Lieutenant (Ret), Maryland State Police

iii

Study of Deaths Following Electro Muscular Disruption
PANEL MEMBERS
Harlan Amandus, Ph.D.
Chief, Analysis and Field Evaluations Branch
Division of Safety Research
National Institute for Occupational Safety and Health

Randy Hanzlick, M.D.
Professor of Forensic Pathology

Emory University School of Medicine.

Chief Medical Examiner

Fulton County Medical Examiner’s Center.

Atlanta, Ga.


William P. Bozeman, M.D. FACEP, FAAEM
Associate Professor, Associate Research Director
Department of Emergency Medicine
Wake Forest University

John C. Hunsaker III, M.D., J.D, Co-Chair
Associate Chief Medical Examiner
Kentucky Justice and Public Safety Cabinet

Yale H. Caplan, Ph.D., DABFT
National Scientific Services
Baltimore, Md.

John Morgan, Ph.D., Co-Chair
Office Director for Science and Technology
National Institute of Justice

Steven C. Clark, Ph.D.
Research and Development Director
National Association of Medical Examiners

Joseph A. Prahlow, M.D.
Forensic Pathologist
South Bend Medical Foundation
Professor of Pathology
Indiana University School of Medicine-South Bend at
the University of Notre Dame
South Bend, Ind.

J. Scott Denton, M.D.
Coroner's Forensic Pathologist
Bloomington, Illinois
Assistant Professor of Pathology
University of Illinois College of Medicine at Peoria

William Oliver, M.D., M.S., M.P.A.
Professor
Director, Autopsy and Forensic Services
Brody Medical School
East Carolina University

Mark Flomenbaum, M.D., Ph.D.
Associate Professor of Pathology and Laboratory
Medicine
Boston University School of Medicine
Lisa Gleason, M.D.
Chief Medical Information Officer
Cardiology Department Head
Electrophysiology Specialist
Naval Medical Center, San Diego, Calif.

Lakshmanan Sathyavagiswaran, M.D., FRCP(C),
FCAP, FACP
Chief Medical Examiner‐Coroner
County of Los Angeles, Calif,
Clinical Professor of Pathology and Medicine, USC
Keck School of Medicine
Clinical Professor of Pathology, UCLA Geffen School
of Medicine

Wendy M. Gunther, M.D., FCAP
Assistant Chief Medical Examiner
Office of the Chief Medical Examiner
Tidewater District, Norfolk, Va.

iv

Study of Deaths Following Electro Muscular Disruption
BRIEFINGS

Geoffrey P. Alpert, Ph.D.
Use of Force Outcomes

John E. Gardner
Managing the ExD Patient

Cynthia Bir, Ph.D.

Javier Sala Mercado, M.D., Ph.D.

A Model to Assess the Effects of Conducted Energy
Device (CED) Exposure on Stressed Animals

Captain Alan Goldberg
Training Model — Conducted Energy Devices
Christine Hall, M.D.
Sudden in Custody Death; the Canadian Experience

Matt Begert
Waveform From TASER®

Anita C. Hege, R.N., M.P.H.
Use of Force Injuries and Pattern of Severity

William Bozeman, M.D.
Use of Force Injuries and Pattern of Severity
EKG Functionality/Conducted Energy Device

James R Jauchum Ph.D
Physiological Response of Repeated Exposure to
TASER®

Michael Cao, M.D.
TASER® Induced Rapid Ventricular Myocardial
Capture

John Kenny, Ph.D.
Overview of JNLWD Funded EMD Research

Joe Cecconi
NIJ Less Lethal Technology Programs

David A. Klinger, Ph.D.
Use of Force Continuum

Theodore C. Chan, M.D.
Gary M. Vilke, M.D.
Cardiac — Respiratory — Metabolic — Effects of
Electro Muscular Disruption (EMD)

Mark W. Kroll, Ph.D.
®
TASER and Ventricular Fibrillation
Phil Lynn
Law Enforcement Perspectives

Stephen Clark, Ph.D.
Literature Review Updates

Charlie Mesloh, Ph.D.
Effectiveness of Less Lethal Devices

John D’Andrea
Joint Non-Lethal Weapons Directorate (JNLWD)
Research Programs

Christopher Mumola,
Deaths in Custody Reporting Program

Andrew Dennis, D,O.
Ventricular Capture;

William Oliver, M.D.
CED-Related Litigations and the Practice of MEs

Robert Walter Ph.D.
Physiologic Effects of Prolonged CED Exposure

Richard J. Servatius, Ph.D.
Volunteer Testing and Pulse Oximetry/Physiological
and Neurocognitive Effects of EMD

Vincent Di Maio, M.D.
Excited Delirium (ExD)

Tommy Sexton
Overview of the Study Population

Jason Disterhoft
TASER® Use: Amnesty International Concerns

Tom Smith
Jeffery Ho, M.D.
Medical Research of TASER® International

Stan Erickson Ph.D.
Study Framework

John Webster, Ph.D.
Modeling the Flow of Electro Muscular Disruption

John Firman
Law Enforcement Perspectives

v

Study of Deaths Following Electro Muscular Disruption

Contents
Acknowledgments...............................................................................................................................iii

Panel Members .................................................................................................................................... iv

Briefings.................................................................................................................................................v

Executive Summary ...........................................................................................................................vii

Methodology.........................................................................................................................................1

1.

Continued Use of CEDs by Law Enforcement....................................................................3


2.

Potential for Moderate, Severe or Secondary Injury.............................................................6


3.

Cardiac Rhythm Issues..............................................................................................................9


4.

Respiratory and Metabolic Issues ..........................................................................................15


5.

CEDs as Contributors to Stress ............................................................................................18


6.

Excited Delirium......................................................................................................................21


7.

Safety Margins of CEDs.........................................................................................................23


8.

Prolonged Exposure................................................................................................................26


9.

Research Associated With the Decision to Use a CED.....................................................30


10.

Post-Event Medical Care ........................................................................................................33


11.

Considerations in Death Investigation .................................................................................36


12.

Considerations in Death Certification ..................................................................................39


Epilogue...............................................................................................................................................45

Glossary of Terms as Used in This Report ...................................................................................47

Appendix A. How a TASER® Conducted Energy Weapon Works............................................51

Appendix B. Definitions for Cause, Mechanism and Manner of Death ...................................56

Appendix C. The Use-of-Force Continuum ..................................................................................58

Appendix D. List of Acronyms Used in this Report…………………………...………….60


vi

Study of Deaths Following Electro Muscular Disruption
Executive Summary
Law enforcement agencies continue to seek alternatives to lethal force and better methods to
subdue individuals in order to minimize injuries and death. Less-lethal technologies have
been used by law enforcement for this purpose extensively since the early 1990s. As of
spring 2010, conducted energy devices (CEDs) causing electro muscular disruption have
been procured by more than 12,000 law enforcement agencies in the United States.
Approximately 260,000 CEDs have been issued to law enforcement officers nationwide.
Police adoption has been driven by two major beliefs: first, that CEDs effectively facilitate
arrests when suspects actively resist law enforcement; second, that CEDs represent a safer
alternative than other use-of-force methods. Studies by law enforcement agencies deploying
CEDs have shown reduced injuries to both officers and suspects in use-of-force encounters
and reduced use of deadly force. More recently, independent researchers have come to
similar conclusions, when appropriate deployment and training policies are in place.
Nonetheless, a number of individuals have died after exposure to a CED during law
enforcement encounters. Some were normal, healthy adults; many were chemically
intoxicated or had heart disease or mental illness. These deaths have given rise to questions
from both law enforcement personnel and the public regarding the safety of CEDs. Because
many gaps remain in the body of knowledge with respect to the effects of CEDs, the
National Institute of Justice (NIJ), the research, development and evaluation agency of the
U.S. Department of Justice, conducted a study, Deaths Following Electro-Muscular
Disruption, to address whether CEDs can contribute to or be the primary cause of death
and, if so, by what mechanisms. The study was directed by a steering group that included
NIJ, the College of American Pathologists, the Centers for Disease Control and Prevention,
and the National Association of Medical Examiners.
To support the study, the steering group appointed a medical panel composed of forensic
pathologist/medical examiners and other relevant physicians or specialists in cardiology,
emergency medicine, epidemiology and toxicology. To avoid a conflict of interest, no
panelists were chosen who had worked as litigation consultants for or against CED
manufacturers. This report contains the findings and recommendations of the medical
panel.
In 2008, NIJ released its interim report, Study of Deaths Following Electro Muscular Disruption:
Interim Report. Among other findings, that report stated, “Although exposure to CED is not
risk free, there is no conclusive medical evidence within the state of current research that
indicates a high risk of serious injury or death from the direct effects of CED exposure.”
The interim report described the risks associated with the use of CEDs and provided a set
of accepted research findings in its summary. The report also provided recommendations
for death investigation, medical response and further research. Although this final report
provides additional, significant detail to many of the findings in the interim report, the study
panel’s interim findings still represent its consensus on the issue of risks associated with
CED use.
vii

Study of Deaths Following Electro Muscular Disruption

This final report provides findings concerning death investigation, CED use, CED-related
health effects, and medical response. The panel recommends a thorough review of the entire
report and the associated research literature for medicolegal personnel and those making
decisions concerning CED deployment and associated policies. The following findings are
provided as those of most general interest to date.
There is no conclusive medical evidence in the current body of research literature that
indicates a high risk of serious injury or death to humans from the direct or indirect
cardiovascular or metabolic effects of short-term CED exposure in healthy, normal,
nonstressed, nonintoxicated persons. Field experience with CED use indicates that shortterm exposure is safe in the vast majority of cases. The risk of death in a CED-related use­
of-force incident is less than 0.25 percent, and it is reasonable to conclude that CEDs do not
cause or contribute to death in the large majority of those cases.
Law enforcement need not refrain from using CEDs to place uncooperative or combative
subjects in custody, provided the devices are used in accordance with accepted national
guidelines and appropriate use-of-force policy. The current literature as a whole suggests that
deployment of a CED has a margin of safety as great as or greater than most alternatives.
Because the physiologic effects of prolonged or repeated CED exposure are not fully
understood, law enforcement officers should refrain, when possible, from continuous
activations of greater than 15 seconds, as few studies have reported on longer time frames.
All deaths following deployment of a CED should be subject to a complete medicolegal
investigation, including a complete autopsy by a forensic pathologist in conjunction with a
medically objective investigation that is independent of law enforcement. The complete
investigation should include the collection of information specific to CED-related deaths,
such as the manner in which and the location where CED darts or prongs were applied. A
recommended checklist is contained in chapter 11, “Considerations in Death Investigation,”
pages 36-37 in this report.
Unlike the risk of secondary injury due to falling or puncture, the risk of human death due
directly or primarily to the electrical effects of CED application has not been conclusively
demonstrated. However, there are anecdotal cases where no other significant risk factor for
death is known. Additionally, current research does not support a substantially increased risk
of cardiac arrhythmia in field situations, even if the CED darts strike the front of the chest.
There are anecdotal cases where no other significant risk factor for death is known and
where the temporal association provides weak circumstantial evidence of causation. The
panel reviewed studies on ventricular fibrillation with respect to dart placement,
demonstration of ventricular fibrillation, pulseless ventricular tachycardia, pulseless electrical
activity in animals, and anecdotal examples of capture in humans wearing cardiac
pacemakers or defibrillators. These studies suggest plausible but unproven mechanisms for
unusual and rare cases of death due to a confluence of unlikely circumstances.

viii

Study of Deaths Following Electro Muscular Disruption
In general, the stress of receiving CED discharge(s) should be considered to be of a
magnitude that is comparable to the stress of other components of subdual. All aspects of
an altercation (including verbal altercation, physical struggle or physical restraint) constitute
stress that may heighten the risk of sudden death in individuals who have pre-existing
cardiac or other significant disease.
Caution is urged in using multiple or prolonged activations of CED as a means to
accomplish subduing the individual. There may be circumstances where repeated or
continuous exposure is required; law enforcement personnel should be aware that the
associated risks are unknown and that most deaths associated with CED use involve multiple
or prolonged discharges.
We offer this report to the police community, the medical community and the public as a
contribution to the many considerations necessarily involved in the use of CEDs and other
types of force by law enforcement. We offer this report to our colleagues involved in all
aspects of medicolegal death investigation to educate them on our findings and to offer
possible approaches to their individual case investigations. We know full well that every case
is unique and that it is extremely difficult to generalize findings or techniques. We in no way
imply that our conclusions or suggestions are the only way to proceed. We offer these for
consideration as aids that might be beneficial in formulating a more complete understanding
of the circumstances, mechanisms or pathophysiology in determining the cause and manner
of death.
It is recommended that law enforcement maintain an ongoing dialogue with medical
examiners/coroners and emergency physicians to discuss effects of all use-of-force
applications (CED use and other modalities) and evaluate procedures involving life
preservation, injury prevention and evidence collection.
Any expert panel brings with it certain limitations. These limitations are due not only to the
limitations of our knowledge but also to the perspectives that the panel members bring to
the table. This is particularly true with respect to the determination of the cause and manner
of death. These differences are not capricious, but derive from varying philosophical
viewpoints and traditions regarding how these deaths should be placed within specific
cultural and legal contexts. The conclusions in this report represent a strong underlying
consensus. In instances when there were disagreements over specific classifications or
diagnostic categorizations, the discussions did not reflect differences in the understanding of
basic underlying scientific principles but rather the differences inherent in specific
jurisdictional-related and historic practices. In fact, there was a strong consensus regarding
the principles of these conclusions even in the context of differences in how they might be
phrased. In addition, the report is based upon the information available to the panel at this
writing. As scientific understanding advances, the opinions of panel members may change to
accommodate new findings.
Findings and conclusions of the research reported here are those of the authors and do not
reflect the official position and policies of their respective organizations or the U.S.
ix

Study of Deaths Following Electro Muscular Disruption
Department of Justice. The products, manufacturers and organizations discussed in this
document are presented for informational purposes only and do not constitute product
approval or endorsement by the U.S. Department of Justice.

x

Study of Deaths Following Electro Muscular Disruption
Methodology
This study was directed by a steering group with representation from the National Institute
of Justice (NIJ), the College of American Pathologists, the Centers for Disease Control and
Prevention, and the National Association of Medical Examiners. To support the study, the
steering group appointed a medical panel composed of forensic pathologists/medical
examiners and other relevant physicians or specialists in cardiology, emergency medicine,
epidemiology and toxicology. To avoid a conflict of interest, no panelists were chosen who
had worked as litigation consultants for or against conducted energy device (CED)
manufacturers. This report contains the findings and recommendations of the medical
panel.
In formulating the findings reported here, the panel conducted mortality reviews of CEDrelated deaths and reviewed the current state of medical research relative to the effects of
CEDs. The panel considered nearly 300 CED-related deaths. In these incidents, (a) CED(s)
was (were) deployed by (a) law enforcement officer(s) on an individual who later died. In the
vast majority of these cases, the original medicolegal investigation concluded that the CED
played no role in the death. The panel concentrated its review on those cases in which a
CED was listed on the death certificate. NIJ and the International Association of Chiefs of
Police worked with several law enforcement agencies to collect information in 22 specific,
documented cases involving CED deployment and death. Time and the availability of
complete case documentation (from the initial 911 call through forensic autopsy) limited the
number of field-based cases reviewed and discussed by the medical panel. However, the
cases reviewed were varied and considered representative of all medicolegal cases of death
following CED deployment. These reviews were intended to elucidate the relationships
between CED use and suspect injury and death and to assist in the development of the
material in this final report. The medical panel did not make conclusions that question the
findings by any official certifier of death in any specific case. Mortality reviews have included
analyses of complete autopsies, findings from the scene investigation, post-exposure
symptoms, post-event medical care, and especially the extent, if any, of natural disease or
chemical substances in a decedent. The panel reviewed theoretical case scenarios to identify
important case-related and interpreted issues regarding the cause, manner and circumstances
of death. The panel also examined the currently recognized causes of sudden deaths, chiefly
involving physical, cardiac, pulmonary, metabolic and thermoregulatory mechanisms.
Evaluation of mortality following the use of CEDs is often challenging because of several
factors: some of the necessary case-specific information can be lacking, human research
studies are limited, and the findings in animal studies may not be extrapolated to humans.
There are also variations among medical examiners and coroners in the stylistic methods and
choices of words used to describe the causes of death and to classify the manner of death.
For a broad review such as this one of the safety of CEDs, these considerations can
compromise case identification and statistical reviews of mortality following deployment of
CEDs.
1


Study of Deaths Following Electro Muscular Disruption
This report provides a consensus view of the panel members from a complete review of the
available peer-reviewed research literature and extensive information concerning the use of
CEDs in the field. The findings have been limited to those conclusions that can be based on
current understanding of the available research and literature. A comprehensive literature
search was conducted to compile and catalog peer-reviewed research articles that addressed
the effects of CED on human subjects. Several resources were used to locate articles, books,
news reports, websites, and other literature dealing with the use of CEDs (i.e., stun guns and
other nonlethal electrical weapons), including, but not limited to: Medline, PubMed,
ScienceDirect, ProQuestJStor, Applied Science and Technology Abstracts and Lexis-Nexis. More than
2,500 sources were identified, of which approximately 175 were selected for this study (i.e.,
peer-reviewed journal articles, which focused on the physiological effects of CED use).
These selected references were divided and distributed to an external panel of forensic
pathologists who reviewed and rated each article for scientific quality and relevance. These
assessments were used to identify the most important research articles for consideration by
the medical panel in this study. In addition, the articles are cited throughout this final report
to support specific conclusions. Finally, through the National Association of Medical
Examiners, the assessments are available to the medicolegal community for reference in
death investigations. The panel urges continued research to improve the medical
understanding of CED effects and has made specific recommendations throughout this
report in that regard. Due to time constraints, some of the most recent research for this
report was reviewed by panel members only.
The panel also consulted stakeholders, experts and other interested parties, such as human
rights groups, law enforcement professionals, clinical physicians, research scientists and
manufacturers of CEDs. The panel observed more than 30 presentations by these invited
experts. It met nine times over three years to discuss these findings and debate their
significance to the investigations and certifications of deaths when CEDs are involved. This
report represents the panel’s best efforts of collaboration and mutual respect for our many
divergent points of view and perspectives.

2


Study of Deaths Following Electro Muscular Disruption
1.

Continued Use of CEDs by Law Enforcement

Conducted energy devices (CEDs) are commonly used by law enforcement agencies. Their
use is associated with overall decreases in suspect and officer injuries when deployed with
appropriate agency policies.1 However, exposure to CED is not risk-free. The safety of these
weapons has been the subject of controversy. CED deployment has been associated with incustody sudden deaths. Comprehensive, independent studies have examined the experience
of police agencies with respect to the decision to deploy CEDs. These studies indicate that
CED deployment by an agency decreases the likelihood of injuries to suspects and officers.
1-3
Field experience with CED use indicates that exposure is safe in the vast majority of
cases.4-6 One prospective study observed a 0.25 percent risk of serious injury (head trauma
or rhabdomyolysis) with CED use, much less than that observed for other subdual options.6
Other studies also indicate that CED-related injuries and deaths are uncommon, especially in
comparison to other force options.7 One review showed that officer and subject injury rates
were much lower during CED use compared to use of empty-handed physical skills,
incapacitating spray or batons, while another indicated that injury rates were substantially
lower with the use of incapacitating sprays and CEDs.1,8
It should be noted that arrestees who are involved in use-of-force incidents are by nature at
higher risk for serious complication and death relative to the overall population. These
individuals are more likely to be drug-intoxicated, be mentally ill or have serious underlying
medical conditions.6 There are more than 600 arrest-related deaths in the United States each
year and roughly 1 million incidents in which police use or threaten to use force.9,10
Nonetheless, the CED is cited as a causative or contributory factor in very few arrest-related
deaths each year.9 In this context, the relative risk of CED deployments appears to be lower
than other use-of-force options.
There is no conclusive medical evidence within the state of current research that indicates a
high risk of serious injury or death from the direct or indirect cardiovascular or metabolic
effects of short-term CED exposure in healthy, normal, nonstressed, nonintoxicated
persons. 11 Current medical research in humans and animals suggests that a single exposure
of less than 15 seconds from a TASER® X-26™ or similar model CED is not a stress of a
magnitude that separates it from the other stress-inducing components of restraint or
subdual.12 Based on cases reviewed by this panel, most adverse reactions and deaths
associated with CED deployment appear to be associated with multiple or prolonged
discharges of the weapons. There is limited research with regard to exposures of greater
than 15 seconds.13,14 Further, extended CED exposure may not be effective in the subdual of
some individuals with high levels of drug intoxication or mental illness. Therefore, if the
CED is ineffective in subduing an individual after a prolonged exposure, law enforcement
officers should consider other options.

3


Study of Deaths Following Electro Muscular Disruption
Conclusions and Recommendations:
From a purely medical perspective, law enforcement need not refrain from deploying CEDs
to place uncooperative or combative subjects in custody, provided the devices are used in
accordance with accepted national guidelines and appropriate use-of-force policy.15,16 Ideally,
use-of-force policy development and post-incident review should be done in consultation
with forensic and/or medical experts.
References
1. MacDonald JM, Kaminski RJ, Smith MR. The effect of less-lethal weapons on injuries in
police use-of-force events. Amer J Pub Health. 2009;99:1-7.
2. Smith MR, Kaminski RJ, Alpert GP, et al. A multi-method evaluation of police use of
force outcomes: final report to the National Institute of Justice. Columbia, SC: University of
South Carolina, 2009.
3. Taylor B, Woods D, Kubu B, et al. Comparing safety outcomes in law enforcement agencies that have
deployed conducted energy devices and a matched comparison group that have not: a quasi-experimental
evaluation. Washington, DC: Police Executive Research Forum. 2009.
4. Eastman AL, Metzger JC, Pepe PE, et al. Conductive electrical devices: A prospective,
population-based study of the medical safety of law enforcement use. J Trauma: Inj Infect Crit
Care. 2008;64:1567-1572.
5. Angelidis M, Basta A, Walsh M, et al. Injuries associated with law enforcement use of
conducted electrical weapons. Acad Emer Med. 2009;16:S229.
6. Bozeman WP, Hauda WE, Heck JJ, et al. Safety and injury profile of conducted electrical
weapons used by law enforcement officers against criminal suspects. Ann Emer Med.
2008;20:1-10.
7. Ho JD, Heegaard WG, Dawes DM, et al. Unexpected arrest-related deaths in America: 12
months of open source surveillance. West J Emer Med. 2009;10:68-73.
8. Jenkinson E, Neeson C, Bleetman A. The relative risk of police use-of-force options:
evaluating the potential for deployment of electronic weaponry. J Clin Forensic Med.
2006;13:229-241.
9. Mumola CJ. Arrest-related deaths in the United States, 2003-2005. Washington, DC: U.S.
Department of Justice, Bureau of Justice Statistics. 2007.
10. Durose MR, Langa PA, Smith EL. Contacts between police and the public, 2005. Washington,
DC: U.S. Department of Justice, Bureau of Justice Statistics. 2007.
11. Bozeman WP, Barnes Jr DG, Winslow III JE, et al. Immediate cardiovascular effects of
the Taser X26 conducted electrical weapon. Emer Med J. 2009;26:567-570.
12. Ho JD, Dawes DM, Cole JB, et al. Lactate and pH evaluation in exhausted humans with
prolonged TASER X26 exposure or continued exertion. Forensic Sci Int. 2009;190:80-86.
13. Jauchem JR, Seaman RL, Klages CM. Physiological effects of Taser C2 conducted energy
weapon. Forensic Sci Med Pathol. 2009;5:189-198.
14. Ho JD, Dawes DM, Cole JB, et al. Human physiological effects of a civilian conducted electrical
weapon application. Minneapolis, MN: Hennepin County Medical Center Study. 2008.
15. American Medical Association. Use of Tasers by law enforcement agencies, report 6 (A-09) of the
4


Study of Deaths Following Electro Muscular Disruption
Council of Science and Public Health. Washington, DC: American Medical Association. 2009.
16. International Association of Chiefs of Police. Electronic control weapons, a model policy of the
International Association of Chiefs of Police. Alexandria, VA: International Association of Chiefs
of Police, 2007.

5


Study of Deaths Following Electro Muscular Disruption
2.

Potential for Moderate, Severe or Secondary Injury

The question often arises whether injuries result from CED exposure, and, if so, to what
degree of severity. Answers to these questions are important for several reasons. First, the
public and law enforcement agencies need to know the risks of injury in order to have a
realistic understanding of risks to persons subjected to CED exposure. This will allow police
agencies to develop protocols that minimize the risk of injury and will help the public place
CED-related injury in the proper context when CEDs are used by law enforcement
personnel. Medical examiners, coroners, other investigators and emergency medical
personnel need to understand the types of injuries that can be expected as well as their
frequency so they can adequately investigate or treat injuries resulting from CED exposure.
Information to address these questions has been derived from case reports of documented
CED-related injuries in humans and from descriptive studies, both prospective and
retrospective, of injuries observed in populations following CED exposure.1-12 Also, some
potential injuries have been identified through review of unpublished case reports.
A practical definition of moderate and severe CED-related injury has been published.2
Moderate injury requires inpatient treatment and/or is expected to result in no more than a
moderate long-term disability. Severe injury involves a threat to life or requires inpatient
treatment and is expected to result in severe long-term disability. The potential for moderate
or severe injury related to CED exposure is low.2, 5, 7, 9, 10, 13-16 Based on published studies,
significant injury has been noted in less than 0.5 percent of those experiencing a CED
deployment, and has been estimated not to exceed 0.7 percent.1 However, darts may cause
puncture wounds or burns.9 Puncture wounds to an eye from a dart could lead to loss of
vision.4,6 Pharyngeal (throat) perforation by a dart has also been reported.11 Potentially fatal
head injuries or skeletal fractures may result from falls due to muscle incapacitation or
intense muscle contraction.8,10 CED strikes to the head have resulted in dart penetration of
the skull, and in unconsciousness and seizures requiring medical care.3,10 CEDs can
potentially produce other secondary or indirect effects that may result in death. Examples
include:
1.	 Using a CED against a person on a steep slope or on a tall structure, resulting in a
fall with traumatic injuries.
2.	 Ignition risk due to sparks from a CED used near flammable materials such as
gasoline, explosives, volatile inhalants such as aerosol sprays, or the flammable
propellant used in pepper spray.
3.	 Using a CED on a person who is in water, resulting in submersion or drowning.
Conclusions and Recommendations:
In summary, the risk of moderate or severe injury or death from a CED exposure, whether
the injury is directly due to darts or indirectly due to secondary events (falls, fractures, etc.) is
probably less than 1 percent. Evidence from use in the field has shown that the risk of death
in a CED-related incident is ≤ 0.25 percent.2 These studies do not conclude that all the
6


Study of Deaths Following Electro Muscular Disruption
deaths were attributable to CED use. The panel views this as an acceptable level of risk
when potential benefits of CED use are considered, such as reductions of serious injuries to
suspects and law enforcement officers and the risk associated with other lethal and less-lethal
options, when used in accordance with appropriate agency policies.17,18 Further study is
needed to better characterize the scope and severity of direct and indirect injuries caused by
CED use.
References
1. Bozeman WP, Winslow JE. Medical aspects of less lethal weapons. Internet J Rescue Disaster
Med. 2005;5:1-11. Available from: ISPUB.com, Sugar Land, TX. Accessed June 14, 2010.
2. Bozeman WP, Hauda II WE, Heck JJ, et al. Safety and injury profile of conducted
electrical weapons used by law enforcement officers against criminal suspects. Ann Emer
Med. 2009;53:480-489.
3. Rehman TU, Yonas H, Marinaro J. Intracranial penetration of a TASER dart. Amer J Emer
Med. 2007;25:733,e3-e4.
4. Chen SL, Richard CK, Murthy RC, et al. Perforating ocular injury by Taser. Clin Exper
Ophth. 2006;34:378-380.
5. Ordog GJ, Wasserberger J, Schlater T, et al. Electronic gun (Taser) injuries. Ann Emer Med.
1987;16:73-78.
6. Han JS, Chopra A, Carr D. Ophthalmic injuries from a TASER. J Can Assoc Emer
Physicians. 2009;11:90-93.
7. Smith MR, Kaminski RJ, Rojek J, et al. The impact of conducted energy devices and other
types of force and resistance on officer and suspect injuries. Policing: Int J Police Strategies
Manage. 2007;30:423-446.
8. Sloane CM, Chan TC, Vilke GM. Thoracic spine compression fracture after TASER
activation. J Emer Med. 2008;34:283-285.
9. Nanthakumar K, Billingsley IM, Masse S, et al. Cardiac electrophysiological consequences
of neuromuscular incapacitating device discharges. J Amer Coll Cardiol. 2006;48:798-804.
10. Mangus BE, Shen LY, Helmer SD, et al. Taser and Taser associated injuries: A case series.
Amer Surgeon. 2008;74:862-865.
11. Al-Jarabah M, Coulston J, Hewin D. Pharyngeal perforation secondary to electrical shock
from a Taser gun. Emer Med J. 2008;25:378.
12. Rivera-Garcia LE, Crown LA, Smith RB. Overview of electronic weapon injury and
emergency department management. Amer J Clin Med. 2008;5:46-49.
13. Pidgeon KC, Bragg S, Ball K, et al. Uncommon cause of death: the use of Taser guns in
South Florida. J Emer Nur. 2008;34:305-307.
14. Braidwood Commission of Inquiry. Restoring public confidence: restricting the use of conducted
energy weapons in British Columbia. Victoria, British Columbia: Braidwood Commission on
Conducted Energy Weapon Use. 2009.
15. American Medical Association. Use of Tasers by law enforcement agencies, report 6 of the Council
on Science and Public Health 6-A-09. Washington, DC: American Medical Association,
Reference Committee D. 2009.
16. Eastman AL, Metzger JC, Pepe PE, et al. Conductive electrical devices: a prospective,
7


Study of Deaths Following Electro Muscular Disruption
population-based study of the medical safety of law enforcement use. J Trauma: Inj Infect Crit
Care. 2008;64:1567-1572.
17. Smith MR, Kaminski RJ, Alpert GP, et al. A multi-method evaluation of police use of force
outcomes: Final report. Columbia, SC: Univ. of South Carolina. 2008.
18. MacDonald JM, Kaminski RJ, Smith MR. The effect of less-lethal weapons on injuries in
police use-of-force events. Amer J Pub Health. 2009;99:1-7.

8


Study of Deaths Following Electro Muscular Disruption
3.

Cardiac Rhythm Issues

There is currently no medical evidence that CEDs pose a significant risk for induced cardiac
dysrhythmia in humans when deployed reasonably. The heart rhythm issues most important
to consider are ventricular fibrillation (VF), ventricular capture (pacing), ventricular
tachycardia (VT), atrial fibrillation and pulseless electrical activity (PEA).
Based on research in swine, the risk of CEDs directly causing ventricular fibrillation is
exceedingly low.1-4 VF is more or less likely depending on the energy vector, i.e., where the
darts of the CED are located relative to the heart. Different vectors appear to have lesser or
greater chance of producing VF with the greatest risk in swine being sternal notch to heart
apex or sternal notch to just above the umbilicus (navel).4
There is one case report in the medical literature documenting VF two minutes after the
collapse of a teenager who was subdued with a CED.5 The proximity of this collapse to
CED use and documented VF argues in favor of an electrically induced cardiac event. A
recent review of in-custody deaths associated with CED use evaluated individuals who
collapsed within 15 minutes of exposure.6 Presenting rhythms were available in 56 subjects.
In 52 subjects bradycardia-asystole or PEA was seen. The rhythm was VF in four subjects (7
percent). Only one patient collapsed within one minute of exposure, as would typically be
expected with VF. Two had a more delayed collapse at five to eight minutes, and one
collapsed before exposure. In-custody deaths rarely occur immediately following use of the
device, but occur more typically minutes to hours later.7 Because a VF-related death would
be expected to be almost immediate, VF is unlikely to be the cause in most of these incustody deaths.
There are telemetry and echocardiographic data in swine to demonstrate rapid ventricular
capture (pacing) from CED use with a transcardiac vector (when the darts are located on
either side of the heart).8-11 In some of these animals the ventricular dysrhythmia did not
terminate with the end of CED discharge and at times led to the death of the animal. The
risk of ventricular capture also appears to be dependent on the vector.12 There are
echocardiographic studies in humans during CED activation, one of which has dart
placement in the chest area over the heart that did not show capture.13-15 All other echo
studies in humans had remote dart placement and did not show capture.16 In human studies,
the CED exposure is typically applied using alligator clips. Subcutaneous dart placement —
such as often occurs during a law enforcement use-of-force incident — is rarely used.
Because device output through alligator clips is typically lower in energy, human studies may
not reflect the full range of cardiac CED exposures. There are recent studies of rhythm
analysis just before, during and after CED discharge showing no sustained dysrhythmia.17-19
Rapid ventricular pacing is a method used by electrophysiologists to induce ventricular
tachycardia, and this may potentially lead to ventricular fibrillation minutes later. While VT
may be pulseless, patients can sometimes be hemodynamically stable for a period of minutes
9


Study of Deaths Following Electro Muscular Disruption
to hours. In other words, a CED may induce rapid ventricular pacing or VT in an individual
who appears to be in satisfactory condition, but this may lead to VF after a short delay.
Currently, there are no documented cases that CEDs have caused this sequence of events in
humans, but it is theoretically possible.
The risks of cardiac arrhythmias or death remain low and make CEDs more favorable than
other weapons. Extended CED discharge(s) in swine where rapid ventricular pacing
occurred has (have) led to death in some of these animals.20 Therefore, it cannot be
concluded that extended discharge in humans is always safe, despite the successful outcomes
of extended discharges documented in the literature.
Pacemakers are implantable cardiac devices that maintain heart rhythm when it gets too slow.
Defibrillators are implantable cardiac devices that can function as pacemakers, but are
designed to detect life-threatening rapid rhythms and shock or stop the abnormal rhythm.
There have been anecdotal, though well-documented, examples of cardiac capture by CEDs
in subjects with implantable cardiac devices. In no case, however, were these events
associated with bad outcomes.21-23 There is a case report of an individual with an implanted
pacemaker demonstrating ventricular capture during CED use.21 It cannot be known if the
presence of the pacemaker or its associated wires facilitated capture in the ventricle. In swine
studies, capture has occurred in the absence of internal wires. An ultrasonographic study did
not replicate this finding in human volunteers,24 and data from field experience does not
indicate that complications from capture by CEDs are common.25-27
Nonetheless, CED use on individuals with pacemakers and defibrillators can be potentially
hazardous. Pacing may be inhibited or asynchronous during CED exposure.28-29 There has
not been a documented case in which a pacemaker has undergone a power-on reset or
triggered an elective replacement indicator (which may be associated with pacemaker
malfunction). Additionally, there has not been a documented case in which CED exposure
caused a long-term change in pacemaker function, such as lead sensing or pacing threshold.
Implantable cardiac defibrillators have been demonstrated to detect CED discharges as
potential ventricular fibrillation and have charged but not activated.23,28 Limiting the duration
of CED discharges will minimize the chance that one of these devices will give an
inappropriate shock.
Risk of ventricular dysrhythmias is exceedingly low in the drive-stun mode of CEDs because
the density of the current in the tissue is much lower in this mode. However, there is a case
report in the literature where a patient documented to be in atrial fibrillation became
combative and was subdued with one drive stun delivered directly over the heart. He was
immediately documented to be in a sinus rhythm thereafter.30 An individual’s heart rhythm
can spontaneously convert from atrial fibrillation to sinus (normal) rhythm. Nonetheless, the
conversion from atrial fibrillation to a sinus rhythm in this case would appear to be
temporally attributable to the CED.
10 


Study of Deaths Following Electro Muscular Disruption
In approximately one-quarter of CED deployments in the field the darts strike the anterior
chest.31 With dart deployment the most likely vector to produce cardiac effect would be near
the heart and in line with the long axis of the heart.12,31 Deployments to other regions of the
body are very unlikely to generate enough current in the region of the heart to cause
ventricular capture or fibrillation. Additionally, when subjects are exposed to CED
deployment in the field they often fall and may land in a prone position, driving darts further
into the chest wall. This decrease in dart-to-heart distance may increase the likelihood of
direct cardiac effects. Individuals of smaller stature may have a shallower distance between
the skin and the heart, so they may be more susceptible to cardiac effects associated with
dart placement near the heart. This possibility is of theoretical concern and has not been
demonstrated.
There is a multitude of ECG and cardiac enzyme data in the literature supporting no
significant long-term effects on the heart by CED use. Autopsies have not demonstrated
evidence of myocardial infarction (heart attack). The available data do not show long-term
blood chemistry changes affecting cardiac function. There are some recent data
demonstrating significant increase in blood acidity (acidosis) in animal models after CED
use.21 Some research has examined the role of exertion in combination with CED effects.
Extreme physical exertion causes an increase in acidosis because of the production of lactate
in the muscles. Severe acidosis can cause spontaneous dysrhythmias that would not be a
direct effect of CED use.32 Additionally, severe acidosis can lead to pulseless electrical
activity which may be a mechanism of sudden death seen after a prolonged struggle. CED
exposure does not appear to worsen the acidosis that is present from exertion alone.33-35
Metabolic effects of CED exposure are detailed elsewhere in this report.
There is a controversial case report of the successful resuscitation of a teenager with bipolar
disorder and polysubstance abuse who was subdued with a CED. He was reportedly found
not to be moving approximately 20 minutes after CED exposure. Emergency medical
services personnel found him to be in asystole shortly thereafter. The individual was
resuscitated and eventually discharged from the hospital with no apparent long-term
deficits.36 In one publication, bradycardia-asystole or PEA was seen in 93 percent of sudden
deaths which quickly followed discharge of CEDs6. Either of these dysrhythmias can be
precipitated by severe acidosis or could be the terminal rhythm following another lifethreatening rhythm. It remains unclear if CED use contributes to the development of PEA
or asystole. Rapid recognition of a possibly reversible dysrhythmia in cases like this is
imperative to allow for attempted resuscitation.
Although sudden death occurs in custody with and without the use of CED, the exact
mechanism of death in many cases is often not clear.7,37,38 Sometimes, individuals who have
been restrained or are in the process of being subdued will stop moving or responding. In
many cases, the individual may simply be passively compliant. In some cases, the individual
may be experiencing a medical emergency related to acidosis, respiratory compromise, or
11


Study of Deaths Following Electro Muscular Disruption
cardiac arrythmia. Therefore, the restrained individual should be constantly monitored for
responsiveness and general medical condition.
Conclusions and Recommendations:
Law enforcement personnel are trained to target center body mass when using CEDs.
TASER® International, Inc., (a major CED manufacturer) has recently recommended a
change in target zone to below the chest. TASER® Bulletin 15 states, “By simply lowering
the preferred target zone by a few inches to lower center mass, the goal of achieving Neuro
Muscular Incapacitation (NMI) can be achieved more effectively while also improving risk
management.”39 The panel does recognize that CED use involving the area of the chest in
front of the heart area is not totally risk-free; current research does not support a
substantially increased risk of cardiac dysrhythmia in field situations from anterior chest
CED dart penetrations.
References
1. Webster JG, Will JA, Sun H, et al. Can Tasers® directly cause ventricular fibrillation? Madison,
WI: University of Wisconsin. 2007.
2. Wu JY, Nimunkar AJ, Sun H, et al. Ventricular fibrillation time constant for swine. Physio
Meas. 2008;29:1209-1219.
3. Wu JY, Sun H, O’Rourke A, et al. Taser blunt probe dart-to-heart distance causing
ventricular fibrillation in pigs. IEEE Trans Biom Eng. 2008;55:2768-2771.
4. Lakkireddy D, Wallick D, Verma A, et al. Cardiac effects of electrical stun guns: does
position of barbs contact make a difference? Pacing Clin Electrophysiology. 2008;31:398-408.
5. Kim PJ, Franklin WH. Ventricular fibrillation after stun-gun discharge. New Eng J Med.
2005;353:958-959.
6. Swerdlow CD, Fishbein MC, Chaman L, et al. Presenting rhythm in sudden deaths
temporally proximate to discharge of TASER conducted electrical weapons. Acad Emer Med.
2009;16:726-739.
7. Ho JD, Heegaard WG, Dawes DM, et al. Unexpected arrest-related deaths in America: 12
months of open source surveillance. West JEM. 2009;10:68-73.
8. Nanthakumar K, Billingsley IM, Masse S, et al. Cardiac electrophysiological consequences
of neuromuscular incapacitating device discharges. J Amer Coll Cardiol. 2006;48:798-804.
9. Nanthakumar K, Masse S, Umapathy K, et al. Cardiac stimulation with high voltage
discharge from stun guns. Can Med Assoc J. 2008;178:1451-1457.
10. Walter RJ, Dennis AJ, Valentino DJ, et al. TASER X26 discharges in swine produce
potentially fatal ventricular arrhythmias. Acad Emer Med. 2008;65:1478-1487.
11. Valentino D, Walter R, Dennis A, et al. TASER discharges capture cardiac rhythm in a
swine model. Acad Emer Med. 2007:S104.
12. Walter RJ, Dennis AJ, Valentino DJ, et al. Taser X26 discharges in swine: ventricular
rhythm capture is dependent on discharge vector. Acad Emer Med. 2008;15:66-68.
13. Ho JD, Reardon R, Lapine A, et al. Echocardiographic determination of cardiac rhythm during
trans-thoracic wireless conducted electrical weapon exposure. Minneapolis, MN: Hennepin County
Medical Center. n.d.
12 


Study of Deaths Following Electro Muscular Disruption
14. Ho JD, Reardon RF, Dawes DM, et al. Ultrasound measurement of cardiac activity during
conducted electrical weapon application in exercising adults. Sorrento, Italy: The Fourth
Mediterranean Emergency Medicine Congress. 2007.
15. Ho JD, Reardon RF, Dawes DM, et al. Echocardiographic evaluation of a TASER-X26
application in the ideal human cardiac axis. Acad Emer Med. 2008;15:838-844.
16. Ho JD, Dawes DM, Reardon R, et al. Cardiac & diaphragm ECHO evaluation during TASER
device drive stun. Minneapolis, MN: Hennepin County Medical Center. 2008.
17. Vilke GM, Sloane C, Levine S, et al. Twelve-lead electrocardiogram monitoring of
subjects before and after voluntary exposure to the Taser X26. Amer J Emer Med. 2008;26:1­
4.
18. Vilke G, Sloane C, Bouton K, et al. Cardiovascular and metabolic effects of the Taser on
human subjects. Acad Emer Med. 2007;14:S104-S105.
19. Bozeman WP, Barnes DG, Winslow JE, et. al. Immediate cardiovascular effects of the
TASER X26 conducted electrical weapon. Emer Med J. 2009;26:567-570.
20. Dennis AJ, Valentino DJ, Walter RJ, et al. Acute effects of TASER X26 discharges in a
swine model. J Trauma Inj Infect Crit Care. 2007;63:581-590.
21. Cao M, Sinbane JS, Gillberg JM, et al. Taser-induced rapid ventricular myocardial capture
demonstrated by pacemaker intracardiac electrograms. J Cardiol Electrophysiology. 2007;18:876­
879.
22. Marine J. Stun guns: a new source of electromagnetic interference for implanted cardiac
devices. Heart Rhythm. 2006;3:342-344.
23. Haegeli LM, Sterns LD, Adam DC, et al. Effect of a Taser shot to the chest of a patient
with an implantable defibrillator. Heart Rhythm. 2006;3:339-341.
24. Ho JD, Dawes DM, Reardon RF, et al. Echocardiographic evaluation of a TASER X26
application in the ideal human cardiac axis. Acad Emer Med. 2008;15:838-844.
25. Bozeman WP, Teacher E. Incidence and outcomes of transcardiac TASER probe
deployments. Acad Emer Med. 2009;16:S196.
26. Bozeman WP. Additional information on TASER safety. Ann Emer Med. 2009;54:758­
759.
27. Swerdlow CD, Fishbein MC, Chaman L, et al. Presenting rhythm in sudden deaths
temporarily proximate to discharge of TASER conducted electrical weapons. Acad Emer
Med. 2009;16:726-39.
28. Lakkireddy D, Khasnis A, Antenacci J, et al. Do electrical stun guns (TASER-X26?)
affect the functional integrity of implantable pacemakers and defibrillators? Eur Soc Cardiol.
2007;9:551-556.
29. Khaja A, Govindaraja G, McDaniel W, et al. Effect of stun gun discharges on pacemaker
function. Circ. 2008;118:S592.
30. Richards KA, Kleuser LP, Kluger J. Fortuitous therapeutic effect of a Taser shock for a
patient in atrial fibrillation. Ann Emer Med. 2008;52:686-688.
31. Bozeman WP, Hauda II WE, Heck JJ, et al. Safety and injury profile of conducted
electrical weapons used by law enforcement officers against criminal suspects. Ann Emer
Med. 2008;20:1-10.
32. American Heart Association. 2005 American Heart Association guidelines for
13 


Study of Deaths Following Electro Muscular Disruption
cardiopulmonary resuscitation and emergency cardiovascular care: Part 7.2: Management of
cardiac arrest. Circ. 2005;112:58-66.
33. Ho JD, Dawes DM, Cole JB et al. Lactate and pH evaluation in exhausted humans with 

prolonged TASER X26 exposure or continued exertion. Forensic Sci Int. 2009;190:80-86.

34. Vilke GM, Sloan CM, Suffecool A, et al. Physiologic effects of the TASER after exercise.

Acad Emer Med. 2009;16:704-10.

35. Ho JD, Dawes DM, Buttman LL, et al. Prolonged TASER use on exhausted humans

does not worsen markers of acidosis. Amer J Emer Med. 2009;27:413-418.

36. Schwarz ES, Barra M, Liao MM. Case report : successful resuscitation of a patient in

asystole after a TASER injury using a hypothermia protocol. Amer J Emer Med. 

2009;27:515,e1-e2.

37. Cevik C, Otabachi M, Miller E, et al. Acute stress cardiomyopathy and deaths associated

with electronic weapons. Int J Cardiol. 2009;132:312-317.

38.Samuels MA. The brain-heart connection. Circ. 2007;116:77-84.

39. Memo regarding Training Bulletin 15.0 regarding medical research update and revised warnings.
Scottsdale, AZ: TASER International, Inc. 2009.

14 


Study of Deaths Following Electro Muscular Disruption
4.

Respiratory and Metabolic Issues

The balance of acid and base in the body is maintained by the respiratory system and the
kidneys. These respond to the metabolic demands of the individual. As with rigorous
exercise, the CED causes muscle contractions that produce lactate in the blood. Lactate
lowers the pH of blood, making it more acidic. Respiratory rates increase to counteract this
effect by reducing the amount of carbon dioxide (CO2) in the blood and thereby mitigating
the effects of the increased lactate. In extreme cases, the increase in blood acidity (referred
to as “acidosis”) could lead to cardiac arrest. Studies of CED effects have examined
respiration, blood chemistry and the effects on muscle groups. In particular, observation of
persons subjected to CED exposure seems to indicate that muscle groups are affected that
fall outside those in the area directly between the darts. For example, CED discharges to the
thorax often result in collapse to the ground, suggesting that there may be a spinal cord
reflex involved that can affect muscle groups under the control of lower spinal cord levels.
If that is the case, it seems reasonable that intercostal (between the ribs) muscles used for
respiration could also be impacted, with an adverse effect on ability to breathe during CED
exposure.
Research to date, however, shows that human subjects seem to maintain the ability to
breathe during exposure to a CED. In fact most evidence suggests hyperventilation with an
increase in respiratory rate, tidal volume, and minute ventilation during CED exposure.
Direct observation of diaphragmatic movement was seen in one study.1 Despite the
hyperventilation, which typically produces an increase in blood pH, a mild decrease in pH
indicating metabolic acidosis is often seen with more prolonged exposures. In conjunction
with this is an increase in lactate consistent with metabolic acidosis. Alcohol consumption
appears to contribute only minimally to an additional decrease in pH or increase in lactate
levels.2
Very little research has been done on the role of CED vectors (i.e., the positioning of the
CED darts) and the effect on respiration. Some studies have examined variable vectors, but
with a focus on cardiac effects. As noted below, it is difficult to examine respiratory effects in
animal studies.
A recent study of 104 volunteers reports that 18 percent of subjects with CED exposure to
the back perceived an inability to breathe during CED exposure, but such inability to breathe
was not documented by direct observation or physiologic tests of breathing capacity. The
researchers concluded that the results pointed mainly to a need for further study. The
medical panel reviewed an unpublished follow-up study using sensors to monitor breathing
directly. That study appears to indicate that CEDs could interfere with the ability to inhale,
depending on dart placement. Breathing is controlled by the phrenic nerve, which originates
in the cervical spinal cord and innervates the diaphragm, in conjunction with intercostal
nerves, which originate in the thoracic spinal cord and innervate the intercostal muscles.
Therefore, if CED exposure interferes with breathing, it may not be an all-or-none
15 


Study of Deaths Following Electro Muscular Disruption
phenomenon. For example, the intercostal muscles may be affected while the diaphragm is
not, or vice versa. Further study with objective measurement of breathing is needed to draw
more definitive conclusions. Such studies should involve both short term CED exposures
and more prolonged or repeated exposures. Hypoventilation could contribute a respiratory
component to any underlying acidosis. With prolonged exposure, if CO2 levels rose
significantly, respirations could be further suppressed from the high CO2 levels despite
termination of CED exposure.
Studies with swine have been conducted using an extended exposure of 80 seconds,
producing significant acidemia as well as hypoventilation. A few of these animals have died.
The animal literature is complicated by the use of sedation that may play a role in
hypoventilation and a failure of respiratory compensation for a metabolic acidosis. In other
words, the animals’ breathing may be compromised by some combination of sedation, CED
exposure and other confounding factors from the experimental design. Animal studies
suggest that the metabolic acidosis is secondary to an increase in lactate produced after
strenuous muscle contraction. In one study, animals were paralyzed to prevent muscle
contraction during CED exposure. In this case, acidosis was much less severe but significant
cardiac effects were still observed.3
There are recent data in the literature of human studies looking at the effect of exercise and
CED exposure and their individual contributions to blood acidosis. CED exposure does not
appear to add to acidosis above and beyond that seen with exercise to exhaustion. CED
exposure without exertion produces only a mild acidosis. 4-6
Conclusions and Recommendations:
Significant acidosis can lead to pulseless electrical activity and may be a mechanism of
sudden death in custody. Of particular concern is the possible role that systemic acidosis
may play in addition to any metabolic abnormalities or drug intoxication seen in excited
delirium, as discussed elsewhere in this report. Further study is required in this area. Until
the role of CEDs with respect to respiration has been researched fully, it would be
appropriate for law enforcement personnel, when possible, to refrain from continuous
activations of longer than 15 seconds. In any case, it is recommended that the medical
condition of the individual be constantly monitored during and after CED exposure,
regardless of the duration of exposure.
In addition to the concerns related to the effect of CED exposure on respiration, there is a
case report in the literature of pharyngeal (throat) perforation from CED discharge.7 This
patient presented with spitting of blood and difficulty breathing.
References
1. Ho JD, Dawes DM, Reardon R, et al. Cardiac & diaphragm ECHO evaluation during TASER
device drive stun. Minneapolis, MN: Hennepin County Medical Center. 2008.
2. Moscati R, Ho J, Dawes D, et al. Physiologic effects of prolonged conducted electrical
16 


Study of Deaths Following Electro Muscular Disruption
weapon discharge on intoxicated adults. Acad Emer Med. 2007;14:63-64.
3. Walter RJ, Dennis AJ, Valentino DJ, et al. TASER X26 discharges in swine produce
potentially fatal ventricular arrhythmias. Acad Emer Med. 2008;15:66-73.
4. Ho JD, Dawes DM, Cole JB, et al. Lactate and pH evaluation in exhausted humans with
prolonged TASER X26 exposure or continued exertion. Forensic Sci Int. 2009;190:80-86.
5. Vilke GM, Sloane CM, Suffecool A, et al. Physiologic effects of the TASER after exercise.
Acad Emer Med. 2009;16:704-710.
6. Ho JD, Dawes DM, Buttman LL, et al. Prolonged TASER use on exhausted humans does
not worsen markers of acidosis. Amer J Emer Med. 2009;27:413-418.
7. Al-Jarabah M, Coulston J, Hewin D. Pharyngeal perforation secondary to electrical shock
from a Taser gun. Emer Med J. 2008;25:378.

17 


Study of Deaths Following Electro Muscular Disruption
5.

CEDs as Contributors to Stress

“Stress,” as used in this discussion, describes the body’s reaction to threat or physical insult,
including but not limited to the adrenaline-related (adrenergic or catecholamine) “flight or
fight” reaction. The literature on the acute and chronic effects of stress is large and will not
be reviewed extensively here.
Whenever law enforcement officers subdue or restrain an individual, they are contributing to
the person’s stress level. All aspects of an altercation (including verbal altercation, flight,
physical struggle, or physical restraint) constitute stress that may heighten the risk of sudden
death, generally from a cardiac dysrhythmia. Whether or not a CED deployment is involved
and regardless of the intent of the officer, it is possible for the actions of an officer to
directly or indirectly contribute to death by inducing stress. Stress induced by the criminal
action of others may be considered a contributing factor in initiating the mechanism of
death in certain individuals with underlying natural disease. For example, if an individual
with a heart condition dies as a result of being the victim of a robbery, the death may be
ruled a homicide caused by the stress of the crime1-3. In a similar fashion, stress may be an
important issue to consider when investigating and certifying deaths following CED use or
when other forms of restraint or subdual are used. One proposed mechanism by which
CED use may contribute to death is by increasing stress, which can potentiate the adrenergic
responses of tachycardia (i.e., rapid heart rate) and elevated blood pressure, making it an
issue related to cause and manner of death determination. There may also be additional
physiologic or metabolic effects, especially when stress is severe or other factors have already
put the individual into a compromised medical condition, as may occur in individuals who
have pre-existing cardiac or other significant disease or who are intoxicated. An important
question is whether or not stress caused by CED exposure is different enough from other
forms of stress during the agitation, restraint or subdual to justify its separate consideration
when certifying death.
The data used to address the stress issue have been derived largely from prospective studies
conducted on human volunteers. Medical research suggests that a single exposure of less
than 15 seconds deployed from a TASER® model X26TM or a similar model CED is not a
stress of a magnitude which separates it from the other stress-inducing components of
restraint or subdual.4 There were no cardiac dysrhythmias among healthy volunteers exposed
to one discharge of a TASER® model X26TM for less than 15 seconds following either
anaerobic exercise, rigorous exercise or exercise to exhaustion.4-6 A study using drive-stun
mode on volunteers also failed to show cardiac rhythm disturbances or diaphragm
disturbances.7 However, because the numbers of subjects in these studies were small, the
subjects were healthy, and the risk of ventricular fibrillation due to a single CED discharge is
very low, the applicability of these studies to field conditions is questionable.

18 


Study of Deaths Following Electro Muscular Disruption
It has been proposed that acute stress can damage the heart muscle. There are several
reports that suggest that acute stress (with catecholamine release) may cause a
cardiomyopathy (or disease of the heart muscle) and be induced in certain individuals during
police confrontation. There are insufficient data to provide diagnostic criteria for such a
syndrome, although some research and case reports exist.8-11 Japanese cardiologists initially
described “acute stress cardiomyopathy” with transient left ventricular apical ballooning and
normal coronary vessels in otherwise healthy, asymptomatic individuals who died in police
custody.8 Such deaths occurred in the absence of CED exposure and are believed to involve
a sudden cardiac dysrhythma induced by a surge in adrenaline. Other studies of CED
exposure have examined parameters such as blood chemistry, cardiac enzymes and blood
gases.5,12,13 Although studies on human volunteers undergoing prolonged (greater than 15
second) CED exposure showed statistically significant changes in blood gases, these changes
(or any respiratory impairment) appear to have limited clinical significance in these healthy
individuals.13,16
Further study is needed to determine the quantity of stress caused by prolonged or repetitive
CED exposure in normal subjects, and larger numbers of human subjects need to be tested.
Similar studies in persons with significant disease or drug intoxication would provide more
useful data. However, it is not ethical to conduct human studies which attempt to replicate
certain “field conditions” (such as drug intoxication with agitation) encountered in CEDassociated, police confrontation deaths. The fatal mechanisms of stress and catecholamine
release need further clarification, and methods to measure and quantify stress effects should
be investigated. Until such methods are developed or more comprehensive field data are
obtained, it is reasonable to infer that the effects of acute stress can be cumulative, and that
the cumulative effects of adrenaline and other factors such as acidosis may increase an
individual’s risk of experiencing a sudden cardiac dysrhythmia.
Conclusions and Recommendations:
Current data on stress induced by CED exposure are limited because the number of persons
studied (sample size) is small and the subjects typically have been healthy volunteers. Further,
interpretations are hampered because reliable markers for catecholamine-related stress and
its complications are not well identified or accepted. Cases of death may exist where the
CED deployment may be the only or predominant inducer of stress. Special attention to
such cases is warranted when considering potential mechanisms of death.
CED exposure may contribute to “stress,” and stress may be an issue related to cause-of­
death determination. All aspects of an altercation (including verbal altercation, physical
struggle or physical restraint) constitute stress that may heighten the risk of sudden death in
individuals who are intoxicated or who have pre-existing cardiac or other significant disease.
Medical research suggests that CED deployment during restraint or subdual is not a
contributor to stress of a magnitude that separates it from the other stress-inducing
components of restraint or subdual.15
19 


Study of Deaths Following Electro Muscular Disruption
References
1. Hanzlick R, Hunsaker JC, Davis GJ. A guide for manner of death classification. Atlanta, GA:
National Association of Medical Examiners. 2002.
2. Davis JH. Can sudden cardiac death be murder? J Forensic Sci. 1978;23:384-387
3. Turner SA, Barnard JJ, Spotswood SD, Prahlow JA. “Homicide by heart attack” revisited. J
Forensic Sic. 2004;49:598-600
4. Dawes D, Ho J, Miner J. The neuroendocrine effects of the TASER X26: A brief report.
Minneapolis, MN: Hennepin County Medical Center. 2009.
5. Vilke GM, Sloane CM, Neuman T, et al. In reply ... physiological effects of the Taser. Ann
Emer Med. 2008;52:85.
6. Ho J, Dawes D, Calkins H, et al. Absence of electrocardiographic change following
prolonged application of a conducted electrical weapon in physically exhausted adults. Acad
Emer Med. 2007;14:128-129.
7. Ho JD, Dawes DM, Reardon R, et al. Cardiac & diaphragm ECHO evaluation during TASER
device drive stun. Minneapolis, MN: Hennepin County Medical Center. 2008.
8. Cevik C, Otabachi M, Miller E, et al. Acute stress cardiomyopathy and deaths associated
with electronic weapons. Int J Cardiol. 2009;132:312-317.
9. Samuels MA, The brain-heart connection, Circ. 2007;116:77-84.
10. Wittstein IS, Thiemann DR, Lima JA, et al. Neurohumoral features of myocardial
stunning due to sudden emotional stress. N Eng J Med. 2005;352:539-548.
11. Martínez-Sellés M. Sudden death in young males after police detention: A new syndrome
of possible cardiovascular origin. Rev Esp Cardiol. 2009;62:101-102.
12. Valentino DJ, Walter RJ, Dennis AJ, et al. Acute effects of MK63 stun device discharges
in miniature swine. Mil Med. 2008;63:581-590.
13. Ho JD, Dawes DM, Miner, JR. Serum biomarker effect of prolonged TASER XREP device
exposure. Minneapolis, MN: Hennepin County Medical Center. 2008.
14. Nixon AA. Police take Taser training; Littleton officers get to use the devices. The
Caledonian-Record News. 2007:1-4.
15. Bouton K, Vilke G, Chan T, Sloane C, Levine S, Neuman T, Levy S, Kolkhorst F,
FACSM. Physiological Effects of a Five Second TASER Exposure. Medicine & Science in Sports &
Exercise, 2007;39:S323.
16. Dawes DM, Ho JD, Johnson MA, Lundin E, Janchar TA, Miner JR. 15-second
conducted electrical weapon exposure does not cause core temperature elevation in nonenvironmentally stressed resting adults. Forensic Sci Int. 2008;176(2-3):253-257.

20 


Study of Deaths Following Electro Muscular Disruption
6.

Excited Delirium

Excited delirium (ExD) is one of several terms that describe a syndrome that is broadly
characterized by agitation, excitability, paranoia, aggression, great strength and
unresponsiveness to pain, and that may be caused by several underlying conditions,
frequently associated with combativeness and elevated body temperature.1-3 ExD-associated
agitated behavior often leads to law enforcement intervention and CED use. The
predominant theory of the underlying etiology of ExD is an excess of catecholamines (such
as adrenaline) or sympathetic nerve stimulation during the excited period. However, a
syndrome, by definition, is a collection of signs and symptoms, not a specific disease. People
with multiple conditions may present in this manner, including drug-induced psychosis,
serotonin syndrome, diabetic ketoacidosis, paranoid schizophrenia and others. Alcohol
withdrawal and head trauma have also been implicated.4 Recent research suggests that
individuals with a history of chronic illicit stimulant abuse may be particularly susceptible to
excited delirium.5
There has been criticism of the term “excited delirium” because its use is generally limited to
medical examiners and emergency medicine physicians whose patients die before a complete
workup is completed that would allow for a more specific diagnosis. Whether one uses the
term or not, ExD-related behavior and medical conditions are well-recognized.
In general, excited delirium may have a mortality of about 10 percent.6 Sympathomimetic
agents include substances such as cocaine, methamphetamine, epinephrine (adrenalin),and
dopamine. There is a subset of ExD-affected people who have sympathomimetic poisoning
with malignant hyperthermia (high body temperature), sometimes associated with elevated
serotonin levels. These cases have a grim prognosis and are at high risk of death regardless
of police actions or method of subdual. In one study of 12 patients who made it to the
hospital, four died and five suffered severe neurologic complications. This correlates well
with other published observations that mortality is about 67 percent for those with a
temperature above 41.5 degrees Celsius (106.7 degrees Fahrenheit).6,7 ExD is frequently but
not always associated with the use of cocaine and other stimulants.8 One study reported that
78 percent of excited delirium cases had serological evidence of stimulant intoxication.9
There are other forms of combative, agitated behavior that require subdual; often grouped
together under the umbrella of emotionally disturbed persons (EDPs). EDPs may be
mistaken for people with excited delirium, and a subset of these may in fact display features
of ExD. However, not all EDPs that require subdual have the syndrome of ExD.
There is ongoing research in how best to manage patients with ExD. However, it is clear that
at least some of these patients are medically unstable and in a rapidly declining state with a
risk of mortality in the short term. This holds true even with medical intervention or in the
absence of CED deployment or other types of subdual. While studies in young, healthy,
21 


Study of Deaths Following Electro Muscular Disruption
drug-free volunteers suggest that CED deployment has inconsequential metabolic and
stress-related effects, no human studies have been performed in situations modeling ExD.10
Because of this uncertainty, the number and duration of the CED discharge(s) should be
generally limited to the minimal amount needed to attain restraint. Police officers should be
aware of ExD-related behavior and indications, especially hyperthermia, which is easy to
recognize and associated with the worst outcomes.
Conclusions and Recommendations:
The “drive-stun” or contact mode of CED use is a pain compliance procedure, and does not
cause muscular incapacitation enabling restraint. Some sources indicate that people suffering
from excited delirium are relatively insensitive to pain as a result of their condition. Some
reports from law enforcement reinforce this view, because there are individuals who do not
appear to be affected by the pain associated with CED exposure. Thus, “drive-stun” mode
and other pain compliance methods should not be repeated in these individuals if they are
found to have little or no initial effect.
References
1. American College of Emergency Physicians. Excited Delirium Task Force White Paper
Report to the Council and Board of Directors. 2009.
2. Dimaio TG, Dimaio JM. Excited delirium syndrome: Cause of death and prevention. CRC Press,
2006.
3. Report of the Panel of mental health and medical experts’ review of excited delirium. Halifax, Nova
Scotia, Canada Department of Justice, 2009.
4. Pacquette M. Excited delirium: Does it exist? Persp Psychiatric Care. 2003;39:93-94.
5. Mash DC, Duque L, Pablo J, et al. Brain biomarkers for identifying excited delirium as a
cause of sudden death. Forensic Sci Int. 2009;190:e13-e19.
6. Samuel E, Williams RB, Ferrell RB. Excited delirium: Consideration of selected medical
and psychiatric issues. Neuropsychiatric Dis Treat. 2009;5:61-66.
7. Gowing LR, et al. The health effects of ecstasy: A literature review. Drug Alcohol Rev.
2002;21:53-63.
8. Stratton SJ, Rogers C, Brickett K, et al. Factors associated with sudden death of
individuals requiring restraint for excited delirium. Amer J Emer Med. 2001;19:187-191.
9. Robison D, Hunt S. Sudden in-custody death syndrome. Topics Emer Med. 2005;27:36-43.
10. Strote J, Hutson HR. Taser use in restraint-related deaths. Prehospital Emer Care.
2006;10:447-450.

22 


Study of Deaths Following Electro Muscular Disruption
7.

Safety Margins of CEDs

Most fatalities involving CED use are in people who have other risk factors for sudden
death. This is a concern for law enforcement, because a large number of arrestees will have
unrecognized clinical states of drug intoxication or pre-existing medical conditions that put
them at risk for sudden, unexpected death, regardless of the type of subdual or restraint
used. The medicolegal death investigator must identify the currently recognized safety
margins of CED deployment in order to evaluate competing possible causes of death. Most
of the deaths reviewed by the panel for this report involved individuals with drug
intoxications or complicating medical conditions or both, thus making judgments about the
relative role of CED exposure in the deaths very difficult.
It is clear that physical injury secondary to dart puncture, fall and other physical effects is a
real though relatively uncommon danger. These are discussed at length elsewhere in the
report, as is the literature regarding the cardiac, respiratory and metabolic effects of CED
use. The latter suggest small risks associated with CED use, especially for healthy individuals.
However, there are groups who may be at risk for sudden death and those who are more
vulnerable to physical insult. These disparate but occasionally overlapping groups include
small children, those with diseased hearts, the elderly and pregnant women. For instance, the
death of a seven-month-old infant following the application of a stun gun by his foster
mother has been reported.1 The small size of this infant, coupled with the nearness of the
contact electrodes to the heart, was postulated as a plausible mechanism for death. Case
reports of fetal death due to exposure to electrical current exist, all involving exposure
significantly more severe than that associated with CED exposure.2 In contrast, one study of
31 pregnant women subjected to electric shock, not from CED deployment, but including
12 V (telephone line), 110 to 220 V (home appliance), and 2000 and 8000 V (electric fence)
current, found no adverse effects to the pregnancies.3 There has been no research or field
study demonstrating a significantly higher or lower risk for CED use with any particular
group.4-7
Unlike the risk of secondary injury due to falling or puncture, the risk of human death due
directly or primarily to the electrical effects of CED application has not been conclusively
demonstrated. However, there are anecdotal cases where no other significant risk factor for
death is known and where the temporal association provides circumstantial evidence of
causation, albeit weak.8 The panel recognizes the distinction between correlation and
causation and that close temporal relationships do not necessarily prove causation. Studies
on ventricular fibrillation with respect to dart placement, demonstration of ventricular
fibrillation, pulseless ventricular tachycardia, or pulseless electrical activity in animals, and
anecdotal examples of ventricular capture in humans with cardiac pacemakers or
defibrillators provide a plausible mechanism for unusual and rare cases of death due to a
confluence of unlikely circumstances. Multiple plausible mechanisms have been proposed
but none proven.9
23 


Study of Deaths Following Electro Muscular Disruption
Many subjects of CED exposure are under the influence of drugs. One study suggested that
cocaine intoxication decreased the risk of arrhythmia in animals, though it was limited by the
lack of controls and the complex manipulation of the animals required by the study. 10
Similarly, a study on prolonged exposure in alcohol-intoxicated adult humans revealed no
significant morbidity.11 Thus, there is currently no basis in scientific research to conclude that
drug use increases or decreases the safety margin of CED exposure. 11
The safety margin of CEDs is subject to the variability in the output of the devices.
Researchers are continuing to study the most common CEDs in use today, the models
X26TM and M26TM from TASER® International, Inc., to determine the variability of their
output. The effect of this output variability on cardiac safety margin is unclear.
Most research has been done using devices from TASER® International, Inc. Medical and
safety data regarding stun batons, CED projectiles and other devices are much more limited.
Although the early data suggest similar results, the current literature is sparse.12-16 Another
manufacturer, Stinger Systems, Inc., manufactures CEDs that are being used in some
agencies and that are purported to have an improved safety margin because they declare to
operate at lower power levels than the TASER® models X26TM or M26TM. Independent
research on Stinger Systems devices is very limited, so the panel could not judge the relative
safety margin of these devices.17
Conclusions and Recommendations:
The literature suggests a substantial safety margin with respect to the use of CEDs when
they are used according to manufacturer’s instructions. However, plausible mechanisms of
injury do exist which make it impossible to exclude direct lethality in every case. The safety
margins of CED use in normal healthy adults may not be applicable in small children, those
with diseased hearts, the elderly, pregnant women and other potentially at-risk individuals.
The effects of CED exposure in these populations are not clearly understood, and more
data are needed. The use of a CED on these individuals when recognized during attempted
subdual should be minimized or avoided unless the situation excludes other reasonable
options.
The use of manual techniques, baton blows, CEDs, other less-lethal technologies and even
taking no action at all will each carry its own risks. All evidence suggests that the use of
CEDs carries with it a risk as low as or lower than most alternatives. While it should be
remembered that unlikely events may occur, it is unreasonable to demand that any
application of force be totally risk-free in all populations at all times. The decision to use a
CED or other options is best left to the reasonable tactical judgment of trained law
enforcement at the scene.

24 


Study of Deaths Following Electro Muscular Disruption
References:
1. Turner MS, Jumbelic ML. Stun gun injuries in the abuse and death of a seven-month old
infant. J Forensic Sci. 2003;48:180-182.
2. Jaffe R, Fejgin M, Aderet B. Fetal death in early pregnancy due to electric current. Acta
Obstet Gynecol Scand. 1986;65:283.
3. Einarson A, Bailey B, Inocencion G, et al. Accidental electric shock in pregnancy: a
prospective cohort study. Am J Obstet Gynecol. 1997;176:678-681.
4. Wu JY, Sun H, O’Rourke AP, et al. Dart-to-heart distance when TASER® causes ventricular
fibrillation in pigs. International Federation for Medical and Biological Engineering
Proceedings. 2007;15:1-5.
5. Wu JY, Sun H , O’Rourke A, et al. Taser blunt probe dart-to-heart distance causing
ventricular fibrillation in pigs. IEEE Trans Biomed Engineering, 2008;55:2768-2771.
6. Webster JG, Will JA, Sun H, et al. Can Tasers® directly cause ventricular fibrillation? Madison,
WI: University of Wisconsin. 2007.
7. Whitehead S. Sorting Taser truths from Taser mythology. Lauren County Emergency Medical
Services: Our Newsletter. 2006;1:13-14.
8. Swerdlow CD, Fishbein MC, Chaman L, et al. Presenting rhythm in sudden deaths
temporally proximate to discharge of TASER conducted electrical weapons. Acad Emer Med.
2009;16:726-739.
9. Cevik C, Otabachi M, Miller E, et al. Acute stress cardiomyopathy and deaths associated
with electronic weapons. Int J Cardiol. 2009;132:312-317.
10. Lakkireddy D, Wallick D, Ryschon K, et al. Effects of cocaine intoxication on the
threshold for stun gun induction of ventricular fibrillation. J Am Coll Cardiol. 2006;48:805­
811.
11. Moscati R, Ho J, Dawes D, et al. Physiologic effects of prolonged conducted electrical
weapon discharge on intoxicated adults. Acad Emerg Med. 2007;14:63-64.
12. Valentino DJ, Walter RJ, Dennis AJ, et al. Acute effects of MK63 stun device discharges
in miniature swine. Mil Med. 2008;173:167-173.
13. Vilke G, Sloane C, Bouton K, et al. Cardiovascular and metabolic effects of the Taser on
human subjects. Acad Emer Med. 2007;14:S104-S105.
14. Dawes DM, Ho JD, Lundin E, et al. The effects of the eXtended range electronic projectile
(XREP) on breathing. Minneapolis, MN: Hennepin County Medical Center, 2008.
15. Dawes DM, Ho JD, Johnson MA, et al. Breathing parameters, venous blood gases, and serum
chemistries with exposure to a new wireless projectile conducted electrical weapon in human volunteers.
Minneapolis, MN: Hennepin County Medical Center. 2007.
16. Burdett-Smith P. Stun gun injury. J Accident Emer Med. 1997;14:402-404.
17. Mesloh C, Henych M, Thompson LF, et al. A qualitative & quantitative analysis of conducted
energy devices: TASER X26 vs. Stinger S200. Washington, DC: U.S. Department of Justice,
National Institute of Justice. 2008.

25 


Study of Deaths Following Electro Muscular Disruption
8. Prolonged Exposure
There is no evidence in animals that indicates a high risk of injury from a single discharge
lasting less than 15 seconds from a TASER® X26TM. Unlike the TASER® X26TM, which
requires the user to hold the trigger to maintain discharges longer than five seconds, other
CEDs will apply a longer discharge without any intervention from the user. The TASER®
C2TM, designed for civilian use, applies a 30-second exposure to a target. Thirty-second
exposure to the output of the TASER® C2TM CED in swine resulted in significant changes in
blood chemistry, although most of the blood changes returned to baseline after the CED
discharge ended. This raises concern for potential detrimental effects due to use of the
TASER C2TM CED.1 However, in one study, 20- to 30-second C2TM CED application in
healthy humans had no significant deleterious effects on their physiology.2
The most common version of the dart-mode CED is the X26TM manufactured and sold by
TASER® for law enforcement. When the trigger is pulled and the darts attach to the skin or
clothing, the device delivers its standard charge as an initial pulse wave of up to 50 kV,
followed by a series of low-current (2.1 milliamps, 70 mJ) pulses for five seconds. The device
has the ability, however, to deliver extensively prolonged and uninterrupted discharges. The
standard discharge cycle may be shortened or prolonged by either maintaining pressure on
the trigger continuously over variable periods of time or by repeatedly depressing and releasing
the trigger over variable intervals limited only by the power in the battery (approximately five
minutes).
There is no standard definition of “prolonged” CED exposure for either continuous
duration or number of multiple interrupted discharges. The majority (93 percent) of CED
exposures in the field involve 15 seconds or less; a significant body of the medical literature
has employed 15 seconds or less of CED exposure.3
After a review of anecdotes that seemed to indicate that multiple exposures were more
hazardous, one researcher recommended in 2005 — without supporting documentation —
that law enforcement agents should “… [l]imit the number of TASER® exposures when
possible (3 is probably a reasonable number).”4 The Police Executive Research Forum
produced guidelines for police concerning CED use including a recommendation that
“[w]hen activating a CED, law enforcement officers should use it for one standard cycle and
stop to evaluate the situation (a standard cycle is five seconds). If subsequent cycles are
necessary, agency policy should restrict the number and duration of those cycles to the
minimum activations necessary to place the subject in custody.”5 The Canadian Police
Research Centre recommended: “… continuous cycling of the TASER for periods
exceeding 15-20 seconds may increase the risk … and should be avoided where practical.”6
Recommendations by the principal manufacturer, TASER® International Inc., have changed
over time. Prior to 2008, they warned against extended duration applications [greater than 5
seconds], noting in particular that darts over the chest or diaphragm may impair respiration
26 


Study of Deaths Following Electro Muscular Disruption
and cautioned that “… [u]sers should avoid prolonged, extended, uninterrupted discharges
or extensive multiple discharges whenever practicable….”7 Their 2008 training bulletin (#14)
concludes that more recent tests on humans demonstrate that “… there are no adverse
effects on heart function or respiration deriving from multiple or prolonged deployments.8
Studies examining the effects of extended exposure in humans to CEDs are limited to
humans exposed to less than 45 seconds. The majority of studies are limited to exposures of
15 seconds or less. Review of deaths following CED exposure indicates that some are
associated with prolonged or multiple discharges of the CED. By contrast, experiments
using healthy human volunteers have found no cardiac dysrhythmias9,10 or respiratory
dysfunction11 following exposures less than 45 seconds. There are no published studies of
humans exposed in excess of 45 seconds. Continuous 15 second application of the X26TM to
either the back or chest of “physically exhausted” adult humans (designed to mimic field
situations), over a 12-inch anatomic spread encompassing the heart, yielded normal
electrocardiograms.13
Bozeman et al. reported in 2008 that among 1,201 cases in which a CED was used, 18.5
percent received CED discharges three or more times.13 In one of these 222 incidents, an
individual sustained significant injury, although it is unclear whether the CED played a role
in the injury. The repeated or continuous exposure of a CED to an actively resisting
individual may not achieve compliance, especially when the individual may be under drug
intoxication or in a state of excited delirium.
The medical risks of repeated or continuous CED exposure beyond the durations studied in
humans are currently unknown, and the role of CEDs in causing death is unclear in these
cases. Uncertain risks associated with the effect of CEDs on respiration should be noted, as
detailed elsewhere in this report (see chapter 4). These risks reinforce the view that
prolonged, continuous CED exposure should be avoided, if possible.
Despite the well recognized limitations implicit in the applicability of results of animal
experiments to humans, the evidence from experiments with swine models indicates that
repeated exposures of over 80 to 90 seconds total duration have been associated with
increased risk of ventricular fibrillation and mortality.14-16 Swine studies involving exposure
durations of 15 seconds or less are not associated with increased risks for ventricular
fibrillation.17 Intermittent exposures appear to be tolerated better than continuous
exposure.15-19
Conclusions and Recommendations:
There may be circumstances in the field that require repeated or continuous exposure to a
CED discharge. Law enforcement personnel should be aware that the associated risks are
unknown and that most deaths associated with CED use involved multiple or prolonged
discharges. Therefore, multiple or prolonged activations of CED as a means to accomplish
subdual should be minimized or avoided.
27 


Study of Deaths Following Electro Muscular Disruption
References
1. Jauchem JR, Seaman RL, Klages CM. Physiological effects of Taser C2 conducted energy
weapon. Forensic Sci Med Path. 2009;5:189-198.
2. Ho JD, Dawes DM, Cole CB, et al. Human physiological effects of a civilian conducted electrical
weapon application. Minneapolis, MN: Hennepin County Medical Center. n.d.
3. Bozeman WP, Hauda II WE, Heck JJ, et al. Safety and injury profile of conducted
electrical weapons used by law enforcement officers against criminal suspects. Ann Emer
Med. 2009;53:480-489.
4. Czarnecki F. Taser use recommendations for law enforcement officers. Miami Beach, FL:
International Association of Chiefs of Police. 2005.
5. Police Executive Research Forum. Conducted energy device policy and training guidelines for
consideration. Washington, DC: PERF Center on Force and Accountability. 2005.
6. Manojlovic D, Hall C, Laur D, et al. Review of conducted energy devices, Technical Report TR-01­
2006. Ottawa, Canada: Canadian Police Research Service. 2005.
7. TASER International, Inc. Restraint during TASER™ system application. Training Bulletin 12.0­
04, TASER Law Enforcement Warnings. Scottsdale, AZ: TASER International, Inc. 2005.
8. TASER International, Inc. Restraint during TASER™ system application. Training Bulletin 14.0­
03, TASER Law Enforcement Warnings. Scottsdale, AZ : TASER International, Inc. 2008.
From Braidwood Commission. Restoring public confidence: restricting the use of conducted energy
weapons in British Columbia. Vancouver, British Columbia, Canada. The Braidwood
Commission on Conducted Energy Weapon Use. 2009.
9. Vilke GM, Sloane CM, Bouton KD, et al. Physiological effects of a conducted electrical
weapon on human subjects. Ann Emer Med. 2007;50:569-575.
10. Moscati R, Ho J, Dawes D, et al. Physiologic effects of prolonged conducted electrical
weapon discharge on intoxicated adults. Acad Emer Med. 2007;14:63-64.
11. Dawes DM, Ho JD, Lundin E, et al. The effects of the eXtended range electronic projectile
(XREP) on breathing. Minneapolis, MN: Hennepin County Medical Center. 2008.
12. Ho J, Dawes D, Calkins H, et al. Absence of electrocardiographic change following
prolonged application of a conducted electrical weapon in physically exhausted adults. Acad
Emer Med. 2007;14:128-129.
13. Bozeman WP, Hauda II WE, Heck JJ, et al. Safety and injury profile of conducted
electrical weapons use by law enforcement officers against criminal suspects. Ann Emer Med.
2008;20:1-10.
14. Dennis AJ, Valentino DJ, Walter RJ, et al. Acute effects of TASER X26 discharges in a
swine model. J Trauma Inj Infect Crit Care. 2007;63:581-590.
15. Walter RJ, Dennis AJ, Valentino DJ, et al. TASER X26 discharges in swine produce
potentially fatal ventricular arrhythmias. Acad Emer Med. 2008;15:66-73.
16. Valentino D, Walter R, Dennis A, et al. TASER discharges capture cardiac rhythm in a
swine model. Acad Emer Med. 2007:S104.
17. Jauchem JR, Cook MC, Beason CW. Blood factors of Sus scrofa following a series of
three TASER electronic control device exposures. Forensic Sci Int. 2008;175:166–70.
18. Jauchem JR, Sherry CJ, Fines DA, et al. Acidosis, lactate, electrolytes, muscle enzymes,
28 


Study of Deaths Following Electro Muscular Disruption
and other factors in the blood of Sus Scrofa following repeated TASER exposures. Forensic
Sci Int. 2006;161:20-30.

29 


Study of Deaths Following Electro Muscular Disruption
9.

Research Associated With the Decision to Use a CED

Law enforcement agencies have deployed CEDs under a variety of circumstances and with a
range of agency policies. The determination of appropriate use-of-force in police action has
an extensive literature that goes well beyond the scope of this panel. There are currently
efforts at a national level to establish guidelines for use within this context.1-3 Individual
departments revise their policies on a continuing basis. In one study of more than 500
agencies, 14.9 percent of agencies surveyed indicated that they were considering changing
their use-of-force policies, and 21 percent already had.4 Some agency policies allow the use
of a CED only as an alternative to deadly force. In many cases, policies permit the use of
CEDs in a wider variety of incidents, including passive resistance scenarios.5 Among other
considerations, agencies must consider the safety aspects of CED deployment when making
these policy decisions. In addition, medical examiners are commonly called upon to offer an
opinion about the level of force that was applied in a custody-related death. The recognition
of appropriate versus inappropriate use of force can have significant medicolegal
consequences.
It was not the mandate of this panel to develop use-of-force policies for law enforcement
agencies or to review CED-related deaths with respect to whether police acted appropriately
in any specific instance or whether specific policies or force options are advisable.
Nonetheless, it is clear that the relative risk associated with CED deployment must be
viewed in relationship to the risks of other alternatives, and not viewed in a vacuum.
Multiple departmental reviews have suggested that injury rates, death rates and complaints
against police drop significantly following the deployment of CEDs. For instance,
deployment of CEDs in Charlotte, N.C., was associated with a 56.4 percent reduction in
officer injury and a 79 percent reduction in suspect injury.6 An independent study has
indicated an increase in in-custody deaths following the adoption of CEDs, based on survey
data, but the role of CEDs in any of these deaths was not examined.7 These results are not
normalized for crime rates or other factors.
Independent studies of use-of-force outcomes involving CEDs have been completed, and
they substantiate the view that CED deployment, in general, decreases the likelihood of
injuries to suspects and officers.5,8-10 Further, national statistical data indicates that, despite
widespread use of CEDs in law enforcement, CED deployment is associated with only a
small proportion of in-custody deaths.11 In the largest independent study to date, involving
12 agencies and more than 24,000 use-of-force cases, the odds of suspect injury decreased
by almost 60 percent when a CED was used.8,9 Officer injuries were either unaffected or
reduced when a CED was used. In contrast, using physical force increased the odds of
injury to officers by more than 300 percent and to suspects by more than 50 percent.8,9 In
general, the outcome data are consistent with medical research and this panel’s review of
deaths following CED deployment. Deployment of CED has a margin of safety as great as
or greater than most alternatives.12-14
30 


Study of Deaths Following Electro Muscular Disruption
Conclusions and Recommendations:
In general, CEDs are safe when used properly. Nonetheless, care should be taken when
CEDs are deployed. Researchers have recommended that passive resisters should not be
subjected to CED use and that CED discharges should be limited to the number needed to
gain control of the suspect.8-10 It has been suggested that CEDs should not be used unless
the only other alternative is lethal force. However, if a goal is minimization of harm, it is
appropriate to use the force application that is associated with the least likelihood of injury.
CED use is associated with a significantly lower risk of injury than physical force, so it
should be considered as an alternative in situations that would otherwise result in the
application of physical force. Police officers need to be aware that, although CEDs provide
an effective alternative to lethal force, it is still possible to misuse the device if it is deployed
outside the bounds of departmental policies derived from national guidelines. Use-of-force
policies are a function of training, cultural context, operational contingencies and scientific
concerns. Beyond the recognition of the lower injury rates to officers and suspects
associated with CED use, it was not the mandate of this panel to make recommendations
for a national use-of-force model or precisely where CED use should be placed within it.
References
1. Cronin JM, Ederheimer JA. Conducted energy devices: Development of standards for consistency and
guidance. Washington, DC: U.S. Department of Justice, Office of Community Oriented
Policing Services, 2006.
2. International Association of Chiefs of Police. Electronic control weapons. Model policy # 64.
Alexandria, VA: International Association of Chiefs of Police. 2008.
3. International Association of Chiefs of Police. Electro-muscular disruption technology: A nine-step
strategy for effective deployment. Alexandria, VA: International Association of Chiefs of Police.
2008.
4. Alpert GP, Dunham R. Understanding police use of force: Officers, suspects, and reciprocity.
Cambridge, England: Cambridge University Press. 2004.
5. Smith MR, Kaminski RJ, Rojek J, et al. The impact of conducted energy devices and other
types of force and resistance on officer and suspect injuries. Policing: Int J Police Strat Manage.
2007;30:423-446.
6. Charlotte-Mecklenburg Police Department. TASER project first-year full deployment study.
Charlotte, NC: Police Department. 2005.
7. Lee BK, Vittinghoff E, Whiteman D, et al. Relation of Taser (electrical stun gun)
deployment to increase in in-custody sudden deaths. Amer J Cardiol. 2009;103:877-880.
8. MacDonald JM, Kaminski RJ, Smith MR. The effect of less lethal weapons on injuries in
police use-of-force events. Amer J Public Health. 2009;99:1-7.
9. Smith MR, Kaminski RJ, Alpert GP, et al. A multi-method evaluation of police use of force
outcomes. Columbia, SC: University of South Carolina. 2009.
10. Taylor B, Woods D, Kubu B, et al. Comparing safety outcomes in police use-of-force cases for law
enforcement agencies that have deployed conducted energy devices and a matched comparison group that have
not: a quasi-experimental evaluation. Washington, DC: Police Executive Research Forum. 2009.
11. Mumola CJ. Arrest-related deaths in the United States, 2003-2005. Washington, DC: U.S.
31 


Study of Deaths Following Electro Muscular Disruption
Department of Justice, Bureau of Justice Statistics. 2007.
12. Eastman AL, Metzger JC, Pepe PE, et al. Conductive electrical devices: A prospective,
population-based study of the medical safety of law enforcement use. J Trauma: Inj Infect Crit
Care. 2008;64:1567-1572.
13. Bozeman WP, Hauda II WE, Heck JJ, et al. Safety and injury profile of conducted
electrical weapons use by law enforcement officers against criminal suspects. Ann Emer Med.
2008;20:1-10.
14. Jenkinson E, Neeson C, Bleetman A. The relative risk of police use-of-force options:
evaluating the potential for deployment of electronic weaponry. J Clin Forensic Med.
2006;13:229-241.

32 


Study of Deaths Following Electro Muscular Disruption
10.

Post-Event Medical Care

Individuals who have received CED discharges may suffer injuries during the incident and
also may have pre-existing medical conditions or traumatic injuries, which should be assessed
by medical personnel. Appropriate medical care should be provided if these are present or
suspected, especially when falls, burns or other trauma occur, or when darts penetrate
obviously sensitive areas of the body.
Medical screening. Some form of medical screening is recommended after all CED
exposures starting at the scene of the incident. This may take the form of jail intake medical
screening, evaluation by emergency medical service (EMS) providers in the field, or by
hospital emergency department personnel.
Dart removal. In most cases, darts embedded in the skin may be removed at the scene by
properly trained medical or law enforcement personnel in accordance with local protocols.
When removing embedded darts, care should be taken to avoid exposure to bloodborne
pathogens. Individuals handling darts should be mindful of sharp points and additional
spines located around the components of the newer CED device projectiles. Medical care
should be provided when darts are located in potentially vulnerable areas such as the face,
eyes, neck, genitals or groin, or if there is concern for underlying injuries, regardless of body
location.1-4
Monitoring in-custody. Ongoing monitoring of suspects while in custody is strongly
recommended. Changes in physical condition or mental status/behavior may occur due to
effects of drugs (which may have been ingested or undergone continued absorption),
medical conditions, or as a result of head trauma or internal injuries. These subjects should
be immediately referred for medical evaluation and appropriate therapy delivered by qualified
specialists.
Outpatient follow-up. In the absence of injuries, no specific medical follow-up is required
after most CED exposures. However, suspects who have an implanted cardiac device
(pacemaker or implanted defibrillator) should be evaluated by a physician and have the
device and its stored data analyzed.5 In cases with ocular injuries or CED discharge near the
eyes, outpatient ophthalmologic follow-up is recommended to exclude complications such as
retinal detachment or delayed cataract formation.2,6 Those reporting or suspected of having
significant medical or psychiatric conditions following CED use should also be evaluated to
determine if they may be CED-related and to provide appropriate care. Although
neuropsychologic dysfunction and complaints (physical, cognitive and emotional) have been
well-documented with non-CED electrical injury, it is not clear at this time if this may also
occur after CED exposure.7
Continued abnormal behavior. A minority of suspects taken into police custody (with or
without CED use) will exhibit continued or ongoing abnormal behavior. Abnormal mental
status and/or increased body temperature in combative or resistive subjects may be
33 


Study of Deaths Following Electro Muscular Disruption
associated with an increased risk for sudden cardiac arrest and death. Underlying medical or
drug-induced conditions (such as hypersympathomimetic states, hyperthermia, acidosis,
excited delirium, rhabdomyolysis and others) may be responsible for extensive struggling and
other behaviors that require subdual by law enforcement, including the use of CEDs. There
could also be underlying changes in body chemistry, hypoxia and/or acidosis due to suspect
behavior and activities prior to subdual and CED use.8 Precautions should be taken during
any form of restraint to allow for reasonable chest movement and airway protection.9
Abnormal agitation and confusion should be treated by law enforcement personnel as a
medical emergency. EMS should be immediately dispatched to the scene when this is
recognized (law enforcement should not wait until a subject is subdued and in custody; EMS
should be called immediately). Further, it must be recognized that a nonmoving or
unresponsive subject may be in a medical crisis (i.e., cardiac arrest) rather than being
intentionally passive.
Emergency medical treatment. In such cases, emergency medical providers should initiate
medical support as soon as it is safe to do so. If warranted, sedation, hydration and cooling
should be provided as soon as possible in addition to standard assessment, resuscitation and
supportive care. Emergency medical services protocols specifying these interventions in the
field may be useful and are already in place in some systems.10
Medical personnel both in the field and in the hospital setting are encouraged to assess and
document vital signs including body temperature and oxygen saturation levels, cardiac
rhythm,9,11 neurologic status, and physical findings. Spinal precautions and diagnostic
evaluations for traumatic injuries may be appropriate based on the history and physical
findings. Blood and urine samples should be obtained early for laboratory studies, which may
include serum glucose, electrolytes, pH, lactate levels, cardiac enzymes, urine toxicology
screen and urine myoglobin, among others.12,13
Forensic aspects of medical care, Some agencies obtain photographs of imbedded CED
darts in the field prior to removal. In cases of critical illness, injuries or death, all darts and
clothing removed during medical care (after photography prior to removal if feasible) should
be retained for investigative purposes by the medical examiner/coroner/law enforcement
agency and handled as evidence. Detailed records of medical treatment should be
maintained in all cases.
Conclusions and Recommendations:
Medical personnel should provide appropriate care to individuals who have received CED
discharges as these individuals may suffer injuries during the incident and may also have pre­
existing medical conditions needing assessment. Medical screening at the scene of the
incident, the proper removal of dart(s), and the ongoing monitoring of individuals in
custody for abnormal physical and behavior changes are crucial procedures. Suspects with
implanted cardiac devices should receive outpatient follow-up as necessary. Detailed records,
34 


Study of Deaths Following Electro Muscular Disruption
including photographs of the scene and body, should be obtained in all cases; these records
should include documentation of medical treatment provided.
References
1. Han JS, Chopra A, Carr D. Ophthalmic injuries from a TASER. J Canadian Assoc Emer
Physicians. 2009;11:90-93.
2. Chen SL, Richard CK, Murthy RC, et al. Perforating ocular injury by Taser. Clin Exper
Ophthal. 2006;34:378-380.
3. Al-Jarabah M, Coulston J, Hewin D. Pharyngeal perforation secondary to electrical shock
from a Taser gun. Emer Med J. 2008;25:378.
4. Rivera-Garcia LE, Crown LA, Smith RB. Overview of electronic weapon injury and
emergency department management. Amer J Clin Med. 2008;5:46-49.
5. Haegeli LM, Sterns LD, Adam DC, et al. Effect of a Taser shot to the chest of a patient
with an implantable defibrillator. Heart Rhythm. 2006;3:339-341.
6. Seth RK, Abedi G, Daccache AJ, et al. Cataract secondary to electrical shock from a Taser
gun. J Cataract Refract Surg. 2007;33:1664-1665.
7. Pliskin NH, Capelli-Schellpfeffer M, Law RT, et al. Neuropsychological symptom
presentation after electrical injury. J Trauma: Inj Infect Crit Care. 1998;44:709-715.
8. Robison D, Hunt S. Sudden in-custody death syndrome. Topics Emer Med. 2005;27:36-43.
9. Strote J, Hutson HR. Taser use in restraint-related deaths, Prehospital Emer Care.
2006;10:447-450.
10. ACEP Excited Delirium Task Force. White paper report on excited delirium syndrome.
Proceedings of the American College of Emergency Physicians Council Meeting, Irving, TX: American
College of Emergency Physicians. 2009.
11. Stratton SJ, Rogers C, Brickett K, et al. Factors associated with sudden death of
individuals requiring restraint for excited delirium. Amer J Emer Med. 2001;19:187-191.
12. Tsai, S.H., Chu, S.J., Hsu, C.W., Cheng, S.M., Yang, S.P. Use and interpretation of cardiac
troponins in the ED. Amer J Emer Med. 2008:26:331-341
13. Pidgeon KC, Bragg S, Ball K, et al. Uncommon cause of death: the use of Taser guns in
South Florida. J Emer Nur. 2008;34:305-307.

35 


Study of Deaths Following Electro Muscular Disruption
11.

Considerations in Death Investigation

If a death occurs following the use of a CED by law enforcement personnel who are
subduing, restraining, or apprehending a subject, the death will be investigated by the
appropriate medical examiner or coroner’s office as an in-custody death. Because deaths
following CED deployment involve both complex and predictable issues, the death
investigation needs to include consideration of information that may not be gathered in a
routine death investigation or other in-custody death investigations. It is not the intent of
this report to provide a comprehensive checklist of tasks which should be performed.
Rather, we are providing what we believe will be helpful suggestions for consideration in the
most important aspects of CED-related death investigations.
The information needed for investigation of death following CED use will need to be
collected by death investigators from multiple sources and at the direction of the medical
examiner or coroner who has ultimate responsibility for determining the cause and manner
of death in the case. Further, the forensic pathologist who performs the autopsy will need to
review such information, perhaps request additional information, and will develop
information from the autopsy examination which may trigger or require additional
investigation. The forensic pathologist who performs the autopsy is an integral part of the
investigative team.
The following information can be useful in establishing facts and should be considered
during the death investigation:
1.	 A timeline of all events with attempts to verify, to the extent possible, the accuracy
of the dates and times of reported events, with specific emphasis on the interval
between CED use, unresponsiveness and death.
2.	 Clarification of CED model and mode of use (drive-stun and/or cartridge mode).
3.	 Access to a comparable CED for familiarization with design and functionality;
4.	 Recent activities of the subject prior to the incident.
5.	 The emotional state of the subject.
6.	 The subject’s reaction to each deployment.
7.	 The subject’s medical conditions as determined by medical history, medical record
review and medical conditions determined at autopsy.
8.	 The subject’s drug use history, including prescription and illicit drugs as well as
alcohol.
9.	 Specific inquiry into the subject’s cardiac history, including review of any
electrocardiograms or other cardiac function or laboratory tests which have been
performed in the past.
10. Specific inquiry into the subject’s seizure history to rule out history of seizures or to
clarify the nature of a past seizure disorder.
11. Review of witness accounts, police reports, use-of-force reports, emergency medical
services records, medical and psychiatric records, and any videos, photographs or
36

Study of Deaths Following Electro Muscular Disruption
digital images of the events.
12. Determination whether body temperature and ambient temperature were established
and documentation of dates and times of such recordings.
13. If death occurred after arrival at a hospital, obtaining blood drawn upon arrival at
the hospital so it may be tested for intoxicants, including medications, if needed.
14. Review of downloaded information from the CED with special attention to an
assessment of the number, duration and timing of CED discharges, including
correlation with other case information to determine successful delivery and the
effects of the discharges on the subject.
15. Assessment of the CED to establish whether it is operating within the

manufacturer’s specifications.

16. Preservation of the CED with batteries (since removal of batteries may alter the
time clock) along with the darts and attached wires.
17. Investigation of the subject’s place of residence or last place to visit to determine if
additional medical history or evidence of drug use exists.
Assuming that the investigation and autopsy are performed and documented/reported in
accordance with the National Institute of Justice’s Death Investigation; A Guide for the Scene
Investigator and the National Association of Medical Examiners’ Forensic Autopsy Performance
Standards,1,2 additional information and procedures that may be helpful, but not warranted in
every case, are as follows:
1.	 Performance of a complete autopsy of the scope usually performed for deaths incustody with appropriate histologic sampling of organs.
2.	 Comprehensive forensic toxicology of autopsy specimens and any retained
antemortem samples, specifically including tests for alcohol, nervous system
stimulants, common drugs of abuse, anti-seizure drugs, and therapeutic drugs often
prescribed for psychiatric disorders.
3.	 Measurement of the thickness of the anterior chest wall from the skin to the rear of
the pre-pericardial sternum at intercostal space between the left fourth and fifth ribs.
4.	 Measurement of the thickness of clothing and chest wall or tissue in the area(s)
where CED darts or prongs penetrated.
5.	 Measurement of the depth of dart penetration.
6.	 Documentation of the CED dart’s(s’) length(s).
7.	 Documentation of dart and stun dart locations and any associated marks or burns.
8.	 Consideration of unusual or atypical current flow paths, such as body to ground,
body to water, body to metal, etc.
9.	 Determination of the nature of any other forms of subdual or restraint that were
employed in the case in question.
10. Removal and evaluation (interrogation) of any implanted cardiac or other electronic
devices.
11. Utilization of appropriate consultants such as cardiologists, cardiac pathologists and
neuropathologists as needed.
37 


Study of Deaths Following Electro Muscular Disruption
The agency responsible for conducting the death investigation should ultimately be
responsible for certifying the cause and manner of death.
References
1. National Medicolegal Review Panel. Death investigation: A guide for the scene investigator.
Washington, DC: U.S. Department of Justice, National Institute of Justice. 1999.
2. Peterson GF, Clark SC. NAME forensic autopsy performance standards. Atlanta, GA: National
Association of Medical Examiners. 2006.

38 


Study of Deaths Following Electro Muscular Disruption
12. Considerations in Death Certification
The medical examiner/coroner is required to determine the cause and manner of death in all
violent, sudden, and unexpected or unusual deaths. Consultant experts in various specialties
may be involved as the case warrants. Any death related to CED deployment would fit into
this category. Available publications describe basic principles regarding death certification
and completion of the cause-of-death section of the death certificate (see also the
definitions in the Glossary of this report).1,2 The manner of death classification (homicide,
suicide, accident, natural or undetermined) is dependent on autopsy findings in conjunction
with all relevant information, including the circumstances surrounding death as determined
by a medically objective investigation independent of law enforcement.3
In a CED-related death, the medical examiner/coroner may choose to exclude any mention
of the CED from the death certificate. In some cases, the death certificate may list the CED
as a causative factor in Part I or as a contributory factor (other significant condition) in Part
II of the cause-of-death statement. In other cases, the CED may be listed as one of the
items in the space provided on the death certificate to describe how injury occurred. Further,
the medical examiner/coroner may choose to classify a CED-related death as a homicide,
whether the CED itself is directly causative or contributory, because the actions of law
enforcement led to the death. In the majority of these cases, a subsequent (nonmedical)
investigation would classify the homicide as justifiable, but it is beyond the scope of the
medical examiner/coroner to make that determination for a death certificate. In other cases,
including those that might list the CED on the death certificate in some way, the death may
be ruled an accident, because the judgment of the medical examiner or coroner would be
that the actions of law enforcement or others involved did not cause death.
Regardless of these classifications, an independent observer should use caution when
interpreting the inclusion of a CED on a death certificate or the classification of the manner
of death as a homicide as an absolute indictment of the CED as the sole or primary reason
for the death. First, the CED-related deaths examined in this study involved a complex set
of circumstances with individuals who were not necessarily healthy and who were often
highly drug-intoxicated. These circumstances make it very difficult to point to the CED as a
particular cause in specific deaths. Second, the decision to list the CED on the death
certificate is subject to the judgment of the individual medical examiner/coroner and
includes medicolegal considerations, experience, and often aspects of local practice and
history.
Among the medical examiners on the panel that produced this report, many cases resulted in
divergent views concerning cause and manner of death, although these disagreements were
within the normal bounds of practice among certifiers of death. It is one objective of this
report to minimize these differences among medical examiners and coroners by improving
the scientific understanding of CED-related injuries and deaths. This is extremely important
39 


Study of Deaths Following Electro Muscular Disruption
to medical examiners and coroners who must complete the death certificate and report the
cause, manner and circumstances of death, including how injury occurred. A consensus is
needed to make certification of death more consistent between cases and between
jurisdictions, while always remaining aware of the need for professional judgment.
For deaths in which the subject is in law enforcement custody or is being apprehended,
restrained or subdued, the medical examiner/coroner must often determine if the
circumstances and findings are most consistent with a natural, accidental, homicidal or
undetermined manner of death.
A major problem with the investigation of in-custody deaths and those in which a CED has
been deployed is obtaining relevant and accurate information regarding the chronology of
events leading up to the time when the subject underwent cardiopulmonary arrest during or
following subdual or restraint. A limiting factor is that like all death investigations, in-custody
death investigations occur after the fact over extended periods of time following the initial
investigation of the scene and circumstances, and often rely on investigative information
gathered by the same law enforcement agency involved in the subdual, restraint or
deployment of a CED.
Both theoretical and real cases reviewed by the medical panel in which CED deployment was
considered as a major factor in causing death were classified as homicide when there were
accurate timelines, independent and objective witness accounts, and strong — almost
immediate — temporal relationships between CED deployment and death. CED use in
these instances could be responsible for initiating or contributing to a fatal sequence of
events. It needs to be emphasized that the manner of death classification on a death
certificate is not an assessment of legal responsibility for the death. From the medical
examiner/coroner standpoint, homicide means that death either occurred at the hands of
another person or resulted from hostile, illegal actions or inactions of another person. For
example, deaths certified as homicide while in the “care” (i.e., custody) of another person
have included the following types of situations:4
1.	 The caregiver has caused the death intentionally.
2.	 The caregiver lacks required licensure or training for the type of care being provided.
3.	 The caregiver consciously disregarded a known likelihood of injury and showed a
wanton and gross disregard for the well-being of the patient (negligence).
In use-of-force deaths, the actions of law enforcement officers may be judged differently
than those of other responders who are classified as “caregivers” even if the officers’ actions
are very similar to those of emergency medical personnel.
In deaths following CED deployment, a certifier of death may determine that the manner of
death was homicide; nonetheless, it may be determined that the officer was acting
appropriately and the homicide was justifiable. Alternatively, the prosecuting attorney may
40 


Study of Deaths Following Electro Muscular Disruption
pursue homicide charges if the law enforcement officer recklessly engaged in conduct and
use of force that created a substantial risk of injury and was not compliant with policy or
guidelines of the department (e.g. repetitive CED discharges when the subject has already
been restrained and handcuffed, or administration of a CED to a compliant individual). In
some cases, an accidental manner of death may be assigned if there is a lethal concentration
of drugs or there are lethal complications of drug use, and subdual or CED use are clearly
not factors contributing to death. In these cases, when the manner of death is classified as
an accident, the certifier of death would be indicating that the actions of the law
enforcement officer, whether appropriate or not, did not contribute to the death of the
individual.
Certification of death following CED deployment can be difficult because:
•	 Information needed to draw conclusions may be of poor quality or not available.
•	 It may be impossible to determine the relative causative or contributory roles of
underlying disease, drug intoxication, drug-induced agitation or delirium, restraint or
subdual, or possible direct electrical or indirect stresses of CED deployment.
After thorough investigation, the certifier may be reasonably certain that CED deployment
did or did not cause or contribute to death. In many cases, the role of CED deployment is
much less clear.
There is debate as to whether CED deployment alone can directly cause death in humans via
electrical effects on the cardiovascular or nervous system, as has been detailed elsewhere in
this report. For the purpose of this discussion it is assumed that such a death may occur. For
example, assume a young, thin, healthy person is not intoxicated, but is resisting arrest and
receives several intentionally deployed, consecutive CED discharges to the anterior chest,
then suddenly dies without other reasonable explanation and no other causative factors are
identified. The death certificate could be worded as follows:

Part I

A. Sudden cardiac death
Due to, or as a consequence of:
B. Conducted energy device discharges
Due to, or as a consequence of:
C.

Part II

OTHER SIGNIFICANT CONDITIONS: Conditions contributing to
death, but not resulting in the underlying cause of death in Part I
41 


Study of Deaths Following Electro Muscular Disruption
Manner of Death
Homicide

Describe how injury occurred
Subdual by law enforcement

If investigation shows a specific single form of restraint or subdual did cause death, such as
head trauma with brain injury from a blow to the head, then death certification may follow
this general example:

Part I

A. Skull fracture with brain contusions
Due to, or as a consequence of:
B. Blunt-force head injury
Due to, or as a consequence of:
C.

Part II

OTHER SIGNIFICANT CONDITIONS: Conditions contributing to
death, but not resulting in the underlying cause of death in Part I

Manner of Death
Homicide

Describe how injury occurred
Struck during subdual by law enforcement for cocaine-induced
agitation

More typically, however, multiple factors are involved such as:
•	 Repeated or prolonged deployment of the CED.
•	 Agitated state or delirium.
•	 Intoxication.
•	 Use of multiple methods of subdual or restraint.
•	 Acidosis, hyperthermia or rhabdomyolysis.
•	 Underlying natural disease such as heart disease, sickle cell trait, etc.
In these less clear-cut cases, the certifier may conclude that subdual contributed to death
because of stress, often in conjunction with a drug-induced agitated state or disease. The
questions become:
•	 Should all contributory factors be itemized or should they simply be combined under
a general category of “stress of restraint” or “stress of subdual?”
•	 Would death have occurred when it did without the restraint?
•	 Should the manner of death be classified as other than homicide?
42 


Study of Deaths Following Electro Muscular Disruption
For example, in a person with cocaine induced agitation and sickle cell trait who the certifier
concludes died from subdual, one option for certifying the death is as follows:
Part I

Cocaine induced delirium resulting in physical subdual
Due to, or as a consequence of:
B.
Due to, or as a consequence of:
C.

Part II
Manner of Death
Homicide

OTHER SIGNIFICANT CONDITIONS: Conditions contributing to
death, but not resulting in the underlying cause of death in Part I
Sickle cell trait
Describe how injury occurred
Cocaine-induced agitation requiring multiple methods of subdual by
law enforcement

In many cases, there are multiple forms of subdual or restraint such as carotid sleeper hold,
pepper spray, handcuffing, hobbling, “hog-tying’” slaps, asp baton strikes, chest
compression, CED deployment, and others. Because it is difficult to differentiate
contributory methods from noncontributory ones, and because of limited space in the “how
injury occurred” section of the death certificate, it may be best to be generic in these
complex cases and simply state that multiple forms of subdual or restraint were used. Of
course, if there is reasonable evidence that one or more specific forms of subdual or
restraint did cause death, such cases can be certified as described above. In general in these
cases, CED deployment should be considered to be a stress of a magnitude that is
comparable to other components of subdual.
Many times, law enforcement officers respond to violent or combative subjects and subdue
or restrain them in order to facilitate medical care. Often, EMS will request law enforcement
officers to come to a scene. In this capacity as a first responder, the distinctions between
medical assistance and law enforcement procedures can be blurred. If a fatal injury results
during medical assistance, the manner of death is usually classified as an accident. If the fatal
injury results during a law enforcement action (even if the motivation is to provide medical
assistance), the manner of death may be classified as homicide.
If there is insufficient information to differentiate between two manners of death, the
manner of death may be certified as undetermined. Some examples in which an
undetermined manner of death may be considered include the following:
a) The autopsy and toxicology findings show no obvious cause of death.
43 


Study of Deaths Following Electro Muscular Disruption
b) Combinations of significant disease and toxicology results that ordinarily would not
be fatal.
c) When death is delayed after lengthy hospitalization and circumstantial details are not
clear.
d) No toxicology screen was done on admission to the hospital and death is delayed.
e) Circumstances of the incident cannot be accurately determined.
Cases reviewed by the panel where CED was determined to be a major factor, and classified
as homicides, were cases in which there was an accurate timeline, an independent witness
observation, and strong, almost immediate, temporal relationship between CED use and
death or initial/sudden collapse or unresponsiveness. When death or the initial/sudden
collapse immediately follows CED use, one can reasonably conclude that the CED would be
responsible for initiating a lethal sequence of events.
References
1. U.S Department of Health and Human Services. Medical examiners' and coroners' handbook on
death registration and fetal death reporting. DHHS Publication No. (PHS) 2003-11110. Hyattsville,
MD: Centers for Disease Control and Prevention, National Center for Health Statistics.
April 2003.
2. Hanzlick R. (ed). Cause of death and the death certificate: Important information for physicians,
coroners, medical examiners, and the public. Northfield, IL: College of American Pathologists.
2006.
3. NAME: A guide for manner of death classification. Marcilene, MO: National Association of
Medical Examiners. 2002.
4. Duncanson E, Richards V, Luce KM, et al. Medical homicide and extreme negligence.
Amer J Forensic Med Path. 2009;30:18-22.

44 


Study of Deaths Following Electro Muscular Disruption
Epilogue
The statements, opinions, and recommendations in this report were developed by consensus
of the panel members. The opinions of the members may change in the future based on
new studies and as more information becomes available. Indeed, the publication of
numerous papers in the time between the release of the interim report and this final report
was instrumental in determining the final recommendations published here. New data
continue to accrue even during the preparation of this final report.
There was a good deal of discussion among the participants regarding the determination of
cause and manner of death from a medicolegal viewpoint. Part of the discussion concerned
our inability to make dogmatic statements about risk in many of these cases. There were also
differing philosophies among participants underlying the placement of specific factors
involved in a death within the chain of causation or contribution. As noted in the disclaimer
at the beginning of this report, these differences do not reflect basic conceptual differences
in the pathophysiology involved, but instead reflect conceptual differences about the
meaning of cause and manner of death. In some cases, of course, the determination of
cause and manner of death is explicit and noncontroversial. But in cases where the “real”
cause must be teased from an interconnecting web of causal factors, differences in opinion
will arise. That does not, however, remove the mandate of the medical examiner in most
cases to assign a specific cause of death.
In addition to these essentially philosophical issues, the fact is that our knowledge and
understanding of CED effects is incomplete. Indeed, there is uncertainty about how exactly
CEDs achieve their effects on the human body. Some propose that the effects of CEDs are
due entirely to electrically induced tetany, while others hypothesize secondary effects due to
nerve stimulation and reflex effects. We do know that CEDs are characterized by the
infliction of excruciating pain. While such a thorough comprehension may not be necessary
to measure the physiologic effects on cardiac function, metabolism, respiration and mortality
associated with CED deployment, it means that all recommendations are subject to revision
as our understanding improves.
During discussions of the use of CEDs with stakeholders, interested parties and
organizations, a recurring concern arose regarding the use of CEDs as punishment or
torture devices. The panel shares the concern that wide deployment of an extremely safe
method of delivering extraordinary pain could also potentiate abuse. Questions about the
ethical infliction of pain in law enforcement are important, and we applaud efforts to
address them, but they are not within the mandate of this panel. Instead, we emphasize that
issues of safety are different and should not be conflated with these other important
concerns.

45 


Study of Deaths Following Electro Muscular Disruption
The panel extends its deep gratitude to the researchers and stakeholders who shared their
knowledge, experience, and extraordinarily diverse perspectives. We greatly appreciate the
efforts of the National Institute of Justice in funding and providing logistical support. We
thank our respective employers, institutions, universities and our families for allowing us the
time and opportunity to perform this function. We extend our respect and thanks to those in
law enforcement and the military who protect our lives, liberty and property. We recognize
our duty to the citizens of these United States, whom we serve and who deserve our best
efforts to ensure that their lives and rights are preserved.

46 


Study of Deaths Following Electro Muscular Disruption
Glossary of Terms as Used in This Report
_______________________________________________________________________
Acidosis — An increase in the acidity (decrease in pH) of the blood; the normal pH of
human blood is 7.4.
Adrenergic response — The epinephrine (adrenaline or catecholamine) response to stress
such as occurs with the “fight or flight” reaction.
Alligator clip — A small metal clip, which is hinged and has teeth, so it resembles the
snout, jaws and teeth of an alligator. In CED research, it is used to attach wires to a research
subject’s clothing.
Apex (of the heart) — The tip (bottom) of the heart closest to the diaphragm.
Cardiac dysrhythmias (arrhythmias) — Abnormal heart rhythms. These can
spontaneously resolve in some instances:
•	 Asystole — Lack of electrical activity and heart function.
•	 Atrial fibrillation — An abnormal heart rhythm where the upper chambers
(atria) are fibrillating (quivering in an unsynchronized fashion). The atria fail to
augment heart output and often cause the heart to beat very rapidly.
•	 Pulseless electrical activity (PEA) — A state where electrical activity can be
recorded from the heart but there is not enough blood flow out of the heart to
maintain a pulse or blood pressure.
•	 Ventricular capture (pacing) — The ability of an external source of energy to
cause the lower chambers (ventricles) of the heart to beat.
•	 Ventricular fibrillation — An abnormal rapid heart rhythm originating in the
lower chambers of the heart. This rhythm does not support flow of blood out
of the heart, causing lack of blood pressure or pulse. This rhythm typically leads
rapidly to unconsciousness and death.
•	 Ventricular tachycardia — An abnormal rapid heart rhythm originating in the
lower chambers of the heart. This rhythm may allow for adequate blood pressure
to support life for a period of time, but may also rapidly lead to death.
Cardiac mechanisms — The ways the heart can fail when injured or sick.
47 


Study of Deaths Following Electro Muscular Disruption
Conducted energy device (CED) — A weapon primarily designed to disrupt a subject’s
central nervous system by means of deploying electrical energy sufficient to cause
uncontrolled muscle contractions and override an individual’s voluntary motor responses.
Darts — Projectiles that are fired from a CED and penetrate the skin; wires are attached to
the darts leading back to the CED.
Dart removal — The act of removing a dart from a person’s body or clothing.
Deployment — Making an item available for use in the field or actually using it in the field.
In this report, deployment means use of the CED on a subject.
Diabetic ketoacidosis — A metabolic abnormality in diabetics which is characterized by
elevated blood sugar and ketones, and may cause abnormal mental function.
Duration — The aggregate period of time that CED shocks are activated.
Dysrhythmia — Any disturbance or irregularity of the heartbeat.
Echocardiography — Ultrasound study of the heart.
Electrocardiogram — A graphic produced by an electrocardiograph, which records the
electrical activity of the heart over time.
Electro muscular disruption — The effect that a CED has on the body. Overrides the
brain’s communication with the body and prevents voluntary control over the muscles.
Emotionally disturbed person (EDP) — A generic term often used by criminal justice
and law enforcement personnel to describe a person with behavioral disturbances which may
be caused by a mental disorder, disease, or a chemically induced state.
Excited delirium — State of extreme mental and physiological excitement, characterized
by extreme agitation, hyperthermia, euphoria, hostility, exceptional strength and endurance
without fatigue.
Hypoventilation — Breathing slower or less deeply than normal, thereby increasing the
amount of carbon dioxide (CO2) in the blood to above normal.
Implantable cardiac device — An electronic device surgically implanted in a person and
usually consisting of a cardiac pacemaker, defibrillator or combination
pacemaker/defibrillator.

48 


Study of Deaths Following Electro Muscular Disruption
•	 Implantable cardiac defibrillator — An implanted cardiac device which has
the ability to recognize and treat abnormal rhythms of the heart. This device can
function as a pacemaker but is also designed to treat life-threatening rhythms
such as ventricular tachycardia and ventricular fibrillation. The device treats these
rhythms by either shocking the heart or rapidly pacing the heart back to a normal
rhythm.
•	 Pacemaker — An implanted cardiac device which causes the heart to beat when
the heart is beating too slow.
Less lethal — A concept of planning and force application that meets an operational or
tactical objective,with less potential for causing death or serious injury than conventional,
more lethal police tactics.
Less-lethal weapon — Any apprehension or restraint device that, when used as designed
and intended, has less potential for causing death or serious injury than conventional police
lethal weapons.
Metabolic mechanisms — The ways the metabolism can fail when a person is injured or
sick.
Pacing threshold — The amount of energy required from a pacemaker to cause the heart
to beat.
Paranoid schizophrenia — A psychotic state in which a person has paranoid delusions
(false beliefs or altered perceptions of reality).
Physical nechanisms — The ways in which illness or injury can compromise heart/lung
function or put body metabolism at risk.
Pulmonary mechanisms — The ways in which lung function can be compromised by
injury or sickness.
Pulse rate — The frequency at which electrical pulse waves are generated.
Pulse wave — A graphic measurement of the wave produced by an impulse of electric
energy.
Respiratory — Relating to the act or process of inhaling (breathing in) and exhaling
(breathing out); breathing, also called ventilation.
Restrain — To control, limit,or prevent movement.
49 


Study of Deaths Following Electro Muscular Disruption

Restraint — A device that restricts movement.
Rhabdomyolysis — Potentially fatal condition resulting from the breakdown of muscle
fibers resulting from metabolic, physical or chemical causes, producing substances that can
damage other organs such as the kidneys.
Sensitive areas — A person’s head, neck, and genital areas, and a female’s breast areas.
Standard CED cycle — A five-second electrical discharge occurring when a CED trigger is
pressed and released. The standard five-second cycle may be shortened by turning the CED
off. (Note: If a CED trigger is pressed and held beyond five seconds, the CED will continue
to deliver an electrical discharge until the trigger is released.)
Sternal notch — The depression in the skin just above the breast bone where the neck
connects to the chest.
Subdual — To bring under control.
Sympathomimetic — A chemical agent or physiologic response which mimics or increases
bodily responses typically caused by the sympathetic nervous system, often due to agents
such as cocaine and amphetamine compounds which increase adrenaline (epinephrine), or
neurotransmitters such as dopamine.
Symptomatology — The combined symptoms of a disease: the symptom complex of a
disease.
Vector — The angle or course of current in this example.

50 


Study of Deaths Following Electro Muscular Disruption
Appendix A. How a TASER® Conducted Energy Weapon Works
PART 3: CONDUCTED ENERGY WEAPONS
Braidwood Commission on Conducted Energy Weapon Use
Models commonly used by Law Enforcement TASER M26 and TASER X26.

a. The Advanced TASER M26

Introduced to the law enforcement community in 1999, the Advanced TASER M26 is a
pistol-shaped weapon. It can be used in two modes:
• Push-stun mode — the end of the weapon is pressed against the target’s body (with an
expended cartridge attached or without a cartridge attached), and a pulsed electrical current
is transferred to the adjacent muscles; or
• Probe mode — when a cartridge is attached to the end of the weapon, it fires two metal
darts or probes (using compressed nitrogen as a propellant), which imbed in the target’s skin
or clothing. The probes, which have hooked tips, can penetrate up to 9 mm into the
subject’s skin. If the probes do not reach the skin due to bulky clothing, the high voltage
creates an arc enabling the current to enter the body. The probes are connected to the
weapon by wires that conduct a pulsed electrical current from the weapon into the target’s
body.
The trigger activates a five-second electrical current cycle, which can be stopped by placing
the safety lever in the safe position, or can be repeated by re-pressing the trigger after the
completion of the first cycle. Holding the trigger down continuously can extend a cycle.
Eight AA nickel metal hydride or alkaline cell batteries power the M26. Depending on the
battery brand used, the electrical current has a pulse rate of 15 or 20 pulses per second, with
a pulse duration of 40 microseconds (40 millionths of a second) full waveform. When the
M26 is held level, the upper probe is propelled in a horizontal direction and the lower probe
is propelled at an eight-degree downward angle, which means that, for every seven feet of
travel, there is a one-foot spread between the probes (or, for every 2.1 metres of travel, there
is a 0.3 metre spread). Four different colour-coded single-use cartridges can be installed, with
different wire lengths — yellow (15 feet), silver (21 feet), green (25 feet), and orange (35
feet). For the M26 to be effective when used in its probe mode, both probes should hit the
subject. To assist the officer in aiming, the M26 emits a red laser beam, which marks where
the upper probe will hit the target. Every cartridge has a unique serial number. When it fires
out the two probes and wires, it also disperses about 30 small discs, called Anti-Felon
Identification tags, with the same serial number on it. This enables investigators to link up
the user of the weapon with the person to whom the cartridge was issued. The M26 has an
LED indicator showing that the laser is on and the weapon is capable of firing, but it does
not indicate whether there is sufficient battery power to fire or discharge. The weapon stores
51 


Study of Deaths Following Electro Muscular Disruption
data about firings, date, and time for approximately 585 firings, which can be downloaded
using an M26 dataport download kit. The manufacturer’s specifications respecting the M26’s
electrical output, which I will discuss in more detail later, include the following:
o	 Voltage:
o	 Peak open circuit arcing voltage — 50,000 V
o	 Peak loaded voltage — 5,000 V
o	 Average voltage over duration of main phase — 3,400 V
o	 Average voltage over full phase — 320 V
o	 Average voltage over one second — 1.3 V
o	 Current: 3.6 mA average (milliamps)
o	 Energy per pulse:
o	 Nominal at main capacitor — 1.76 joules
o	 Delivered into load — 0.50 joules
o	 Power rating:
o Nominal at main capacitor — 26 watts at 15 pulses per second
o Nominal delivered into load — 7.39 watts at 15 pulses per second
However, Mr. Reilly testified that an electrical shock can be delivered across several inches
of air and if one probe hits the subject and the other probe falls on wet ground, the subject
may still receive a shock.

b. The TASER X26

The manufacturer introduced its X26 model, for law enforcement and military use, in 2003.
It was more compact, 60 percent lighter, and designed to be carried in a holster on an
officer’s service belt. The X26’s specifications are similar to the M26, except for the
following:
o	 Batteries — digital power magazine (two 3-volt lithium batteries, as used in digital
cameras)
o	 Pulse rate — 19 pulses per second
o	 Pulse duration — 100 microseconds (100 millionths of a second)
o	 Peak loaded voltage — 1,200 V
o	 Average voltage over duration of main phase — 400 V
o	 Average voltage over full phase — 350 V
o	 Average voltage over one second — 0.76 V
o	 Current — 2.1 mA average
o	 Energy per pulse:
o	 Nominal at main capacitors — 0.36 joules
o	 Delivered into load — 0.07 joules
o	 Power rating:
o	 Nominal at main capacitors — 6.84 watts
o	 Delivered into load — 1.33 watts
52 


Study of Deaths Following Electro Muscular Disruption
o	 LED display — a two-digit display of remaining digital power magazine energy
percentage, burst time, warranty expiration, unit temperature, illumination status, and
current time and date.
o	 Data storage — stores time, date, burst duration, unit temperature, and remaining
digital power magazine energy percentage for approximately 1,500 firings. The data
can be downloaded using a USB data interface module.
o	 Video and audio — available with an optional video and audio recorder that is
activated when the safety switch is armed. It is capable of recording for up to 90
minutes.
In order to understand how a conducted energy weapon works, a basic understanding of
electricity is required. I am indebted to Mr. J. Patrick Reilly, from the Applied Physics
Laboratory of Johns Hopkins University, for his very informative presentation during our
public forums. Much of the explanation that follows is based on what he said and his
PowerPoint presentation.
To begin with a question, if putting my finger into a 120-volt light socket could kill me, why
could I walk away from a 50,000-volt shock from a conducted energy weapon? There are
two reasons. First, the “peak open circuit arcing voltage” is rated at 50,000 volts when
nothing is connected to the probes, such as when the officer is testing the weapon by
creating an electrical arc between the two electrodes. When the weapon is under load (such
as when imbedded in a person’s skin or clothing), the voltage is much less — 7,000 volts for
the M26 and 1,300 volts for the X26, according to Mr. Reilly. Second, the duration of the
conducted energy weapon pulse is short. In the case of the wiring in our homes, the
electrical current is continuous. However, in a conducted energy weapon, a new electrical
pulse begins 19 times every second. The actual duration of each of these pulses is much
briefer — 30 microseconds (30 millionths of a second) with the M26 and 80 microseconds
(80 millionths of a second) with the X26. The pulse durations of 30 and 80 microseconds are
taken from Mr. Reilly’s presentation. According to the manufacturer’s specifications, the
pulse durations are 40 and 100 microseconds for the M26 and X26 respectively.
There is an important reason why a conducted energy weapon needs 50,000 volts. This
voltage (analogous to pressure in a water hose) is required in order to create an electric arc
that bridges an air gap. For example, if one of the probes is imbedded in clothing and does
not touch the skin, the high voltage creates an arc between the probe and the skin, enabling
the electrical current to enter the body. Similarly, although the outer layer of a person’s skin
(the corneum) is dry and normally a poor conductor, the high voltage breaks down the
dryness and makes the skin a good conductor.
Turning now to current (analogous to the water flow rate in a hose, such as litres per
minute), the manufacturer’s specifications state that the M26 has a current of 3.6 milliamps
(3.6 thousandths of an ampere) average, and the X26 has a current of 2.1 milliamps (2.1
thousandths of an ampere) average. Mr. Reilly, on the other hand, cites the M26 as having a
53 


Study of Deaths Following Electro Muscular Disruption
peak output current of 17 amperes, and the X26 as having a peak output current of 3
amperes. He explained the difference between his numbers and the manufacturer’s numbers
as follows. His numbers measure the actual amperage during a pulse, whereas the
manufacturer’s numbers are an average over the total time period, during and between
pulses. In his view, average current is irrelevant to electrostimulation.
According to Mr. Reilly, “delivered charge” is the best indicator of the potential
electrostimulation. It is measured in coulombs, which is analogous to the volume of water
delivered by a hose during a set period of time. The significant point is that both the M26
and the X26 have an almost identical “delivered charge” for each pulse — approximately
100 micro-coulombs (or 100 millionths of a coulomb). This is so because of the differing
currents and pulse durations of the two models, as shown in Table 1.
Table 1. Delivered charge of M26 and X26 models
Current
Pulse duration

M26

X26

30 microseconds

80 microseconds

17 amperes per pulse

3 amperes per pulse

To give a sense of what effect 100 micro-coulombs of delivered charge would have on a
person, Mr. Reilly conducted laboratory experiments with human subjects, who were
subjected to brief high-voltage pulses on their forearms. Subjects reported pain on average at
0.5 micro-coulombs, and intolerable pain at 1.0 micro-coulombs. This is to be contrasted to
the delivered charge of 100 micro-coulombs from each pulse of a conducted energy weapon,
which delivers 95 pulses over a five-second period.
The purpose of the electrical current is different, depending on the mode used:
• Push-stun mode — if the trigger is pulled when the end of the conducted energy weapon
is pressed against the person’s skin (e.g., arm). The electrodes are close together, which
means that the electrical current is localized to the muscles in that area. In that case it serves
a pain compliance purpose, to persuade the person to let go of something, or to otherwise
comply in order to avoid further shocks.
• Probe mode — when the probes are deployed they are normally imbedded in the person
farther apart than the electrodes are in the push-stun mode. In that case, the electrical
current spreads out more and goes deeper into the body, engaging more and more excited
tissue. In addition to the same pain experienced in the push-stun mode, the electrical current
now interferes with the person’s neuromuscular system. The person typically becomes
incapacitated, and falls to the ground with no ability to put his or her hands out to break the
fall.
54 


Study of Deaths Following Electro Muscular Disruption
When the five-second cycle is over, the pain and/or incapacitation is over, and the person’s
normal strength returns immediately.
From the Braidwood Commission of Inquiry. Restoring public confidence: Restricting the use of conducted
energy weapons in British Columbia. Victoria, British Columbia: Braidwood Commission on Conducted
Energy Weapon Use. 2009.

55 


Study of Deaths Following Electro Muscular Disruption
Appendix B. Definitions for Cause, Mechanism and Manner of Death
Background, The study steering group presented definitions for Cause, Mechanism and
Manner of Death for review and comment by the Medical Panel in January 2008. The
definitions herein were revised in April 2008 and will serve to guide mortality reviews of
those cases of interest to the study.
The underlying (or proximate) cause of death is
(a) the disease or injury, or combination of the two, that initiated the

pathophysiologic sequence of events leading to death 

OR

(b) the circumstances of the event [accident or violence] that produced the fatal
injury.
The proximate cause of death is always etiologically specific.
The immediate cause of death is the terminal disease, injury, medical complication or
pathophysiologic condition resulting from the underlying cause or circumstance and directly
preceding death.
The underlying cause of death and the immediate cause may either exist simultaneously or
be separated by variable spans of time.
An intermediate (or intervening) cause of death is a disease or condition with fatal
potential that occurs at any time between the underlying cause of death and the immediate
cause of death and is a result of the underlying cause.
There may be no, one or multiple intermediate causes of death.
A contributory cause of death is any or all significant disease[s], injuries, or
pathophysiologic condition[s] that existed at death and that may have fatal potential, but did
not lead to or result in the underlying cause of death.
There may be no, one or multiple contributory causes of death.
The mechanism of death constitutes the fatal pathophysiologic derangement[s] resulting
from the underlying cause of death.
The mechanism of death is one or more complication[s] of the underlying cause of death,
and:
•	 Is a disturbance of physiology and/or biochemistry.
•	 Is the derangement by means of which the underlying cause of death effects the
lethal outcome.
56

Study of Deaths Following Electro Muscular Disruption
•	 May have more than one cause.
•	 Is never etiologically specific.
The manner of death is a classification of the circumstances of how death occurred. It is
derived from correlation of all investigative and scientific components of the death
investigation.
In most jurisdictions in the United States the subdivision of manner of death is as follows:
•	 Natural — Solely due to disease processes.
•	 Unnatural (or violent) — Due to external agencies (injury of any kind, including
the toxic effects of chemicals) either exclusively or in concert with natural
conditions. These may be:
•	 Homicide.
•	 Suicide.
•	 Accident.
•	 Undetermined — When neither unnatural nor natural manner of death can be
determined ─ OR ─ if the cause of death is known to be unnatural, but
investigation cannot distinguish the subcategories.
Guidelines for Cause (COD) and Manner (MOD) of Death as Used in This
Document:
Cause and manner of death are the medical opinions of the certifier based on information
available at the time of certification.
COD — Reasonable medical and investigative probability, or a preponderance of all
scientific and investigative data.
MOD — Reasonable discretion by the investigating certifier, correlating all pertinent case
data.
Cause and manner of death are subject to change if new information relevant and material
to the investigation emerges.
(N.B. — Certification of a death as homicide does not imply criminal culpability, which is a
determination solely in the jurisdiction of the justice system.)

57 


Study of Deaths Following Electro Muscular Disruption
Appendix C. The Use-of-Force Continuum
Most law enforcement agencies have policies that guide their use of force. These policies
describe an escalating series of actions an officer may take to resolve a situation. This
continuum generally has many levels, and officers are instructed to respond with a level of
force appropriate to the situation at hand, acknowledging that the officer may move or skip
from one part of the continuum to another in a matter of seconds.
An example of one of many use-of-force continuums follows:
•	 Officer Presence — No force is used. Considered the best way to resolve a
situation.
o	 The mere presence of a law enforcement officer works to deter crime or
diffuse a situation.
o	 Officers’ attitudes are professional and nonthreatening.
•	 Verbalization — Force is not physical.
o	 Officers issue calm, nonthreatening commands, such as “Let me see your
identification and registration.”
o	 Officers may increase their volume and shorten commands in an attempt to
gain compliance. Short commands might include “Stop,” or “Don’t move.”
•	 Empty-Hand Control — Officers use bodily force to gain control of a

situation.

o	 Soft technique. Officers use grabs, holds and joint locks to restrain an
individual.
o	 Hard technique. Officers use punches and kicks to restrain an individual.
•	 Less-Lethal Methods — Officers use less-lethal technologies to gain control
of a situation.
o	 Blunt impact. Officers may use a baton or projectile to immobilize a
combative person.
o	 Chemical. Officers may use chemical sprays or projectiles embedded with
chemicals to restrain an individual (e.g., pepper spray).
o	 Conducted energy devices (CEDs). Officers may use CEDs to
immobilize an individual. CEDs discharge a high-voltage, low-amperage jolt
of electricity at a distance. (See chapter 9 on Research Associated With the
Decision to Use a CED
58

Study of Deaths Following Electro Muscular Disruption

•	 Lethal Force — Officers use lethal weapons to gain control of a situation.
Should only be used if a suspect poses a serious threat to the officer or
another individual.
o	 Officers use deadly weapons such as firearms to stop an individual's actions.

USE OF FORCE CONnNUUM

t
FIREARMS AND
STRIKETO VITAL AREAS

lEVEL AVE

lEVEL FOUR

LEVEL THREE

HARD

TEaetIOUeS
SOFT

TEcttNtOUES

OC. COME ALONGS

AND WRiST LOCKS
CLEAR AND
OEUBERATE

LEVEL TWO

LEVEL ONE

STRIKES AHO
TAKEOOWNS

OFACER
PRESENCE

PHYSICAL APPEARANCE
PROFESSlONAL8EARING

I
Figure 1. Descriptive diagram of one of many use-of-force continuums

59 


Study of Deaths Following Electro Muscular Disruption
Appendix D: List of Acronyms Used in this Report

List of Acronyms Used in This Report
CED: Conducted energy device
COD: Cause of death
ECG: Electrocardiograph/electrocardiographic
EDP: Emotionally disturbed person
EMD: Electro muscular disruption
EMS: Emergency medical service(s)
ExD: Excited delirium
JNLWD: Joint Non-Lethal Weapons Directorate
kJ: kilojoule
kV: kilovolt
LED: Light-emitting diode
mA: milliampere
mJ: millijoule
MOD: Manner of death
NIJ: National Institute of Justice
NMI: Neuro muscular incapacitation
PEA: Pulseless electrical activity
USB: Universal service bus
V: volt
VF: Ventricular fibrillation
VT: Ventricular tachycardia

60 


About the National Institute of Justice
The National Institute of Justice — the research, development and
evaluation agency of the Department of Justice — is dedicated
to improving our knowledge and understanding of crime and justice
issues through science. NIJ provides objective and independent
knowledge and tools to reduce crime and promote justice,
particularly at the state and local levels.
NIJ’s pursuit of this mission is guided by the following principles:

Our principal authorities are
derived from:
•	

The Omnibus Crime Control and
Safe Streets Act of 1968, amended
(see 42 USC §§ 3721-3723)

•	

Title II of the Homeland Security Act
of 2002

•	

Justice For All Act, 2004

•	 Research can make a difference in individual lives, in the
safety of communities and in creating a more effective
and fair justice system.
•	 Government-funded research must adhere to processes of
fair and open competition guided by rigorous peer review.

To find out more about the National
Institute of Justice, please visit:

•	 NIJ’s research agenda must respond to the real world needs
of victims, communities and criminal justice professionals.

www.nij.gov

•	 NIJ must encourage and support innovative and rigorous
research methods that can provide answers to basic research
questions as well as practical, applied solutions to crime.

National Criminal Justice
Reference Service
P.O. Box 6000
Rockville, MD 20849-6000
800-851-3420
www.ncjrs.gov

•	 Partnerships with other agencies and organizations, public
and private, are essential to NIJ’s success.

The National Institute of Justice is a component of the Office of Justice
Programs, which also includes the Bureau of Assistance; the Bureau
of Justice Statistics; the Community Capacity Development Office;
the Office for Victims of Crime; the Office of Juvenile Justice and
Delinquency Prevention; and the Office of Sex Offender Sentencing,
Monitoring, Apprehending, Registering, and Tracking (SMART).

or contact:

*NCJ~233432*

Washington, DC 20531
Official Business
Penalty for Private Use $300

NCJ 233432

PreSOrTeD STANDArD
POSTAge & feeS PAID
DOJ/NIJ
PermIT NO. g–91

MAY 2011

U.S. Department of Justice
Office of Justice Programs
National Institute of Justice