New Studies Counter Plaintiffs’ CEW Arguments

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When allegations of excessive force involve use of a CEW, plaintiffs’ attorneys or their hired experts may raise a couple of stock arguments:

  1. The suspect was not able to comply with the officer’s commands because he could not recover promptly enough from the electronic “stunning”;
  2. When the suspect has died and an autopsy fails to identify any other cause of death, the CEW must have been responsible because the fatality so closely followed the device’s application.

New studies provide evidence with which to challenge both assertions.

First, the issue of lingering incapacitation….

Researchers document psychomotor recovery time from CEW exposure

This study was sponsored by the U.S. military in hopes of confirming a reliable, non-lethal option for controlling possible suicide bombers when they approach checkpoints in combat zones.

“They wanted recovery time from a CEW exposure precisely measured,” researcher Dr. Mark Kroll told Force Science News Kroll, “apparently in hopes there would be enough residual effect during which soldiers could achieve some measure of control before a bomber could detonate his explosives.

“There had not previously been a scientific, peer-reviewed study of this issue done.”

Kroll, an adjunct professor of biomedical engineering at the University of Minnesota and at California’s Cal Poly University, wrote the study paper in collaboration with Dr. John Criscione, an associate professor of biomedical engineering at Texas A&M University, who supervised the actual testing and was the study’s primary researcher.


The subject pool consisted of 32 volunteers (29 of them males) from a CEW training class at the Austin (TX) Police Academy. They ranged in age from 21 to 55.

Each was positioned face-down on a padded mat so that arms and hands could move easily. Current from a TASER X26 CEW was conducted to each for a standard 5-second cycle via alligator-clip electrodes attached to the shoulder and waist to simulate an ideal, exceptionally broad-spread probe placement. This was designed “to achieve maximal CEW-induced control of the upper extremities,” the researchers note.

The subjects were instructed that as soon as the CEW exposure began, they should “immediately” press a button on a box that was placed on the floor in front of them, to measure their psychomotor capability and speed.


Two of the subjects were able to “move their arms in a purposeful manner” even during the CEW exposure. While their movements were “slow and coarse,” they were able to reach and press the button at 3.09 and 4.70 seconds after the start of the exposure.

As for the others, the response time once the CEW exposure ended ranged from 0.31 to 2.99 seconds. “The typical subject took slightly over 1 second–in essence, no recovery time–to move his dominant arm forward, place it on the button box, and push the button,” Kroll says.

“These response times were equivalent to ‘normal’ reaction and movement times of control-group subjects who performed the test in response to hearing a buzzer signal.”

In interviews after their CEW exposure:
  • 75% of the volunteers said they remained conscious of their surroundings during the exposure
  • 91% could hear and 81% could see during that time (5 closed their eyes)
  • 91% said they’d be able to understand commands during an exposure.

“For the military, the study was a bit of a disappointment because the near-zero recovery time doesn’t serve their purpose,” Kroll says. “But for law enforcement, this is great news because it refutes plaintiff claims of being unable to quickly comply with officer commands.”

In their paper, Criscione and Kroll cite a number of court cases in which “misunderstandings of CEW effects,” including recovery times, have been used unfairly against officers in court proceedings. “I’ve seen many variants of misunderstanding,” Kroll told FSN, “from claims of temporary blindness to unconsciousness for minutes to hours after an exposure. Hopefully, our findings will help in establishing a more realistic picture.”

The researchers’ report, “Incapacitation recovery times from a conductive electrical weapon exposure,” appears in the journal Forensic Science, Medicine, Pathology. An abstract of their paper can be accessed free by clicking here. The full study is available there for a fee.

Unexplained sudden cardiac deaths not associated just with CEWs

As to the implication that CEW exposure is a likely cause of sudden cardiac death, that, too, seems to be more an example of plaintiff mythology than a logical conclusion.

Consider two new studies passed to FSN by Atty. Michael Brave, a use-of-force instructor at this year’s annual conference of the International Law Enforcement Educators and Trainers Assn. (ILEETA) and national/international litigation counsel for TASER International, Inc.

These studies investigated sudden cardiac deaths that occurred among “benign” civilians who had no exposure to confrontations with law enforcement or to CEWs. The findings are “so very important,” Brave says, because they put the sudden cardiac death issue “in a meaningful perspective.”


A team of researchers, headed by Dr. Kimberly Harmon of the University of Washington Sports Medicine Center, reviewed autopsy reports and other documentation concerning National Collegiate Athletic Assn. (NCAA) athletes who died suddenly under nontraumatic circumstances during a recent five-year period.

More than 40 cases were analyzed by a panel that included sports medicine physicians, a cardiac pathologist, a cardiomyopathy specialist, a genetic cardiologist, and an electrophysiologist, all with sudden-death expertise.

In most cases, fatalities were attributed to one or another of various heart-related problems. But nearly one-third (31%) of the sudden deaths went unexplained at autopsy. Indeed, this was the single most common autopsy finding.

This result is compatible, Harmon’s group reports, with similar studies of other athletes and of U.S. military personnel. Among the latter, unexplained nontraumatic sudden cardiac deaths that occurred during training over a 25-year period accounted for 35% of cases investigated.

Sudden death mysteries frequently arise outside of law enforcement, Brave points out, and the findings from these other populations tend to undermine speculation that CEW exposure is a probable decisive factor.

Harmon’s study, published by the journal Circulation: Arrhythmia and Electrophysiology, can be accessed free by clicking here


A dozen medical researchers in Denmark, led by Dr. Bjarke Risgaard, for the first time analyzed the deaths of all persons throughout that country aged 1-49 who succumbed to “sudden, natural unexpected deaths” during a recent three-year period.

Among the sudden-death victims who were autopsied, the team found that 67% died of “structural heart disease”–the most common generalized cause of fatality. However, in 31% of cases “death remained unexplained after autopsy,” the researchers report–a finding identical to that of the Harmon group above.

Toxicology tests were positive for illegal and/or prescription drugs in 70% of the unexplained Danish deaths. But none of those cases had a “toxicological profile” that would explain the deaths, according to forensic pathologists.

Bottom line: There is much about sudden death that simply “is not fully understood.”

A free abstract of the Danish study, also published in Circulation, is available by clicking here.

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