Most of Dr. Kroll’s presentation at the use-of-force conference (see: previous FSN) dealt with persistent myths about the alleged electrical dangers of CEWs, particularly claims that these control weapons can cause electrocution and fatal heart disruptions.
The world’s most prolific inventor of cardiac-related medical devices, Kroll is renowned as one of the top international authorities on the effects of electricity on the human body.
The targets of his remarks were what he terms “rogue” medical examiners and coroners. These, he said, are pathology practitioners who, because of limited training, inexperience, anti-police bias, pressure to be conclusive, and/or a profound misunderstanding of how electricity works, identify CEWs as the culprits in arrest-related fatalities where no other cause of death is readily apparent.
ELECTRICITY 101
Kroll disputed some assertions that shocks from a CEW have been fatal by explaining some relevant fundamentals about electricity.
First, he compared CEWs to a common and essentially benign source of shock: electric fences. Under prevailing safety standards, an electric fence can deliver up to 8 watts of short-pulse electricity when touched, likely resulting in some pain or discomfort but far from being lethal. In contrast, the TASER X26E delivers only 1.9 watts, “not even close” to the allowed output of an electric fence, Kroll said.
Similarly, the X26 discharges the equivalent of 13 milliamperes (mA) of household AC current. By international safety standards, Kroll said, up to 35 mA is considered safe for humans and the threshold for seriously dangerous consequences is considered to be above 100 mA.
“Electricity is not like poison,” Kroll stressed. “It does not ‘build up’ in the human body by extended or repeated exposure, and it does not combine with other stressors to produce an enhanced effect. So a cumulative number of seconds of CEW exposure does not increase the risk of serious injury or death.
“If an electrical current is strong enough to electrocute it will do so in and of itself in one to five seconds,” he said. “Prolonged delivery of weaker currents has essentially no effect. The number of trigger pulls of a CEW may seem alarming to a judge or jury that doesn’t understand electricity but scientifically it’s irrelevant in terms of life-threatening danger.”
Research suggests that the greatest risk of fatal results from a CEW would be if a probe were to penetrate to within one-eighth of an inch of the heart or to actually touch that vital organ. “Dart-to-heart distance is critical,” Kroll said. “Theoretically, proximity closer than about three millimeters could induce ventricular fibrillation and cause death, but that hasn’t happened yet, after more than 3,000,000 TASER exposures. And according to scientific studies, that depth of penetration is highly unlikely with any subject weighing more than 56 pounds.”
Yet in some cases medical examiners have claimed that CEW shock caused a fatal heart disruption where probes struck far away from the heart (including only to the back) or where there had been no probe penetration at all, Kroll charged.
COUNTER-TACTICS
Kroll recommends that police authorities try to establish dialog about the realities of non-shooting ARDs with their local medical examiner. “Offer to forward scientific papers about these deaths, if the pathologist is open to it,” he suggests.
If the ME seems disinterested or uninformed, it may be wise to have an alternative, independent pathologist lined up to supplement his or her findings in the event of a controversial fatality.
“Arrest-related death is a well-recognized syndrome, often with no single pathological mechanism that can be identified as a cause of death,” Kroll said. “Medical examiners need to understand that some fatalities simply cannot be explained. Better to acknowledge that in official rulings than to erroneously blame a valuable and overwhelmingly safe police weapon that scientifically could not have been the cause.”
Additional reports from the Miami-Dade PD’s use-of-force conference will be carried in future editions of Force Science News.