Medical Panel Issues Interim Findings on Stun Gun Safety by John Morgan, Ph.D. uring the three-year period from the trade name Taser® — has become the 2003 to 2005, 47 states and the less-lethal device of choice for a grow- D District of Columbia reported 2,002 ing number of law enforcement agencies. arrest-related deaths to the Bureau of Justice CEDs use a high-voltage, low-power charge Statistics’ Deaths in Custody Reporting of electricity to induce involuntary muscle Program.1 For many years, police leaders contractions that cause temporary incapaci- have sought alternatives to lethal force tation. Industry reports suggest that approxi- and better methods to subdue individuals mately 11,500 law enforcement agencies to limit injuries and death. around the country have acquired CEDs, with approximately 260,000 devices now Less-lethal devices have been used by law deployed. In 2003, TASER International enforcement for decades; during the early introduced the Taser X26®, the conducted- 1990s, pepper spray became the less-lethal energy device most widely used by law option of choice for law enforcement and enforcement today. corrections agencies. Although pepper spray is inherently safer than lethal-force options Although studies by law enforcement and may be preferable to blunt-force meth- agencies have found that the deployment ods, many advocates were concerned that of CEDs reduced injuries to officers and pepper spray was associated with in-custody suspects,3 a significant number of indivi- deaths. The National Institute of Justice duals have died after CED exposure. (NIJ) reviewed those cases and, in 2003, Some were normal healthy adults; others issued a report that found pepper spray were chemically dependent or had heart was safe and effective.2 disease or mental illness. These deaths have given rise to questions from law In recent years, electro-muscular-disruption enforcement and the public regarding technology — also known as conducted- the safety of CEDs. energy devices (CEDs) or stun guns or by 20 NIJ JOURNAL / ISSUE NO. 261 Because many gaps remain in the body of knowledge with respect to the effects Although exposure to CEDs is not risk free, of CEDs, NIJ sponsored an independent NIJ’s medical panel found no conclusive research program to address the safety and effectiveness of CEDs and a study to medical evidence in current research that address whether CEDs can contribute to or cause mortality and, if so, in what ways. indicates a high risk of serious injury or death An interim report on this study was recently released. Deaths Following Electro Muscular from the direct effects of CED exposure. Disruption is available at http://www.ncjrs. gov/pdffiles1/nij/222981.pdf; a final report is expected in 2009. by drug exposure.5 Human subject testing was performed with police volunteers The study is being conducted by an expert during training to determine the effects medical panel assembled by NIJ. The panel of CED exposure on healthy individuals, reviewed the full range of current scien- especially with respect to changes in heart tific research, reviewed a number of CED- function and blood chemistry. Field data associated deaths and held substantive collection provides information about how discussions with industry, academia and CEDs are used and how they affect a community advocates. At this time, many range of individuals in real-world settings. questions about the safety of CEDs cannot Some field data were retrospective, based be answered based on current research, on reconstruction of information in police especially with respect to at-risk individuals. reports. Other field data were collected by Nonetheless, although exposure to CEDs medical personnel soon after the use of is not risk free, NIJ’s medical panel found CEDs by law enforcement.6 no conclusive medical evidence in current research that indicates a high risk of serious These studies have improved the under- injury or death from the direct effects of standing of the safety and effectiveness CED exposure. of CEDs. Researchers at the University of Wisconsin found that CEDs can directly NIJ’s Research Program “electrocute” the heart rhythm, although the chance of this happening is quite small.7 Prior to NIJ’s involvement, most of the Theoretically, this can happen only in individ- relevant research in this field had been uals with very little distance from their skin industry sponsored. Although much of surface to their pericardium, the sack around this prior work had been published in peer- the heart muscle. Research published in reviewed journals, some questions had 2007 shows that CEDs can cause heart been raised about the influence of industry fibrillation (a dangerously disturbed heart funding on the results. For its CED safety rhythm) in people with pacemakers, pre- studies, NIJ funded researchers, physicians sumably because the CED shock can and other professionals who have never travel down the electrical leads of the been employed by companies in the field, pacemaker device.8 including TASER International, Inc.4 Device manufacturers did cooperate with and pro- One concern with CEDs has been that vide important information to NIJ-sponsored they cause involuntary muscle contractions researchers and studies. and thus might cause muscle breakdown, changes in blood chemistry, and perhaps NIJ’s research program has included three resulting heart failure. Physiological testing main types of study. In general, physiological has not shown significant signs that these research provided a controlled way to exam- problems actually occur.9 CED exposure ine the limits of CED exposure and how can cause a small, temporary increase in such exposure might affect at-risk popula- lactate, similar to what might be seen tions, such as individuals with high body during moderate exercise. This result temperature or who were compromised confirms industry studies. 21 NIJ JOURNAL / ISSUE NO. 261 death, whether he or she ingested drugs or The panel said that law enforcement engaged in a physical struggle. need not refrain from deploying CEDs, Many police departments are working with provided the devices are used in accordance emergency medical responders to deal with excited delirium cases more effectively. with accepted national guidelines. In Dade County, Fla., responders have implemented protocols based on Canadian research to reduce the risk of death in these individuals. Interventions include sedation Cases of Excited Delirium with the drug Versed and reduction in body temperature using chilled intravenous fluids. Supporters of the use of CEDs attribute Although not recommending Dade County’s many in-custody deaths to a syndrome protocol specifically, NIJ’s interim report on called excited delirium. Excited delirium is in-custody deaths does support active inter- not a medical diagnosis, but a term describ- vention in excited delirium cases, which may ing people who may have psychosis or drug include cooling, sedation and hydration. intoxication. These individuals may show great strength, agitation and violent behav- The Panel’s Recommendations ior. Their body temperature will often be very elevated, to potentially lethal levels. As stated earlier, the NIJ medical panel noted that, at this time, many questions Law enforcement officers encounter sus- about the safety of CEDs cannot be pects in excited delirium frequently and answered based on current research, must use force to subdue them. People in especially with respect to at-risk individuals. excited delirium are at high risk of death The panel found, however, that there is no even if they do not encounter a police offi- conclusive medical evidence to indicate a cer and even if a CED or other weapon is high risk of serious injury or death from the not used against them. These individuals direct effects of CED exposure. In fact, field must be calmed and their body temperature experiences in many police departments reduced as soon as possible to avoid indicate that exposure is safe in the vast sudden death. majority of cases.10 Therefore, the panel said, law enforcement need not refrain Although preliminary data from physiologi- from deploying CEDs, provided the devices cal studies suggest that CEDs may increase are used in accordance with accepted the risk of sudden death in cases of excited national guidelines. (See Electronic Control delirium, NIJ’s study panel concluded in Weapons, a model policy of the International its interim report that CEDs do not directly Association of Chiefs of Police.11) cause death in excited delirium cases. The panel noted that this does not mean that The panel’s interim report includes sig- CEDs are entirely ruled out from having a nificant recommendations for post-event role in such deaths. Everything that happens medical care and investigation of in-custody to a person that causes excited delirium deaths. It is not possible, the panel said, to and stresses a person in excited delirium reach a definitive conclusion concerning the may be a contributing factor in his or her role of less-lethal devices in a death unless the relevant facts have been established about the incident and the decedent. The About the Author report also includes a bibliography of scien- tific papers that have been systematically John Morgan is the Deputy Director for Science and Technology reviewed for their relevance and quality. at the National Institute of Justice. He co-chaired the Steering Group This bibliography represents an authoritative of NIJ’s study, Deaths Following Electro Muscular Disruption. foundation for the inclusion or exclusion 22 NIJ JOURNAL / ISSUE NO. 261 of CEDs in deaths. Although it does not the development of new models to replicate include every possible source of information, excited delirium. the bibliography does represent a reliable 5. Webster, J.G., J.A. Will, H. Sun, J.Y. Wu, set of information accepted by the NIJ A.P. O’Rourke, S.M. Huebner, and P.S.