The panel reviewed nearly 300 cases, from 1999 to 2005, in which people died after police shot them with stun guns, but found most of the deaths were caused by underlying health problems and other issues. Of those cases, the experts examined 22 in which the use of stun guns was listed as an official cause of death.
The study released this week by the department's research arm, the National Institute of Justice, concludes that it's appropriate for officers to use stun guns to subdue unruly or uncooperative suspects, as long as police adhere to "accepted national guidelines and appropriate use-of-force policy." It also makes several recommendations, including medical screenings for all people shot with stun guns.
The experts also noted that evidence shows the risk of death from a stun gun-related incident is less than 0.25 percent, and there's no conclusive evidence that stun guns cause permanent health problems.
"What this study suggests is, indeed, less-than-lethal technologies ... can be effectively used by law enforcement," said John Laub, director of the National Institute of Justice.
The study began more than six years ago after Amnesty International and other groups blamed stun guns for the deaths of many people in police custody. Both Amnesty International and the United Nations Committee Against Torture have called the use of stun guns a form of torture in some cases.
More than 12,000 law enforcement agencies nationwide had issued about 260,000 stun guns to officers as of spring of last year, the study said. Of the more than 600 arrest-related deaths in the U.S. each year, there are very few cases in which stun guns are cited as the cause or contributory factor, the report said.
Officials at Taser International, the maker of the leading stun guns, said Thursday that there are no peer-reviewed medical studies that have found that prolonged or repeated use of Tasers causes death. In 2009, however, the company advised Taser users to try to avoid shooting people in the chest, because of a very low risk of a health problem.
Police across the country have faced heated criticism for stun gun deaths.
In the Utah case, two Hurricane police officers were involved in the deployment of a Taser on the 32-year-old Cardall as he suffered a bipolar episode on the side of State Road 59 near Hurricane on June 9, 2009.
His wife, Anna, had called 911 to report her husband behaving erratically, and told dispatchers her husband was unarmed, had bipolar disorder and had taken Seroquel, a medicine used to treat manic episodes associated with the disorder. Cardall was naked and trying to direct traffic. The lawsuit alleges police could have contained him differently. The complaint, which is pending in federal court, also alleges several missteps made by Officer Ken Thompson and Lynn Excell, Hurricane police chief, at the scene, including the following:
• Thompson deployed a Taser 42 seconds after arriving at the scene, despite information from a 911 dispatcher that Cardall was bipolar and had taken medication and was waiting for it to take effect. Dispatchers told officers that Cardall spoke of meeting the president and was jumping in front of cars on the road indications of mental illness.
• Thompson and Excell responded to the scene, despite the fact that the incident was outside of Hurricane city limits and should have been handled by Washington County deputies, who were en route at the time Thompson used his Taser.
• When Thompson arrived at the scene, the 156-pound Cardall, nude and unarmed, was no longer running in the road. Thompson drew his Taser immediately and began shouting commands without trying to engage Cardall in a conversation to defuse the situation. When Thompson yelled, "Come here," Cardall put his hands in the air.
• Thompson and Excell did not make any effort to take Cardall into custody after he was hit by a Taser once and remained on the ground. Cardall was breathing and moaning after the first Taser cycle. Thompson waited only two seconds before firing a second shot at Cardall; Excell then rolled Cardall facedown in the gravel and handcuffed him.
The state Medical Examiner's Office determined Cardall died of "ventricular fibrillation following conducted energy weapon deployment during a manic episode with psychotic features."
Peter Stirba, a Salt Lake City attorney representing the Hurricane Police Department, has maintained Hurricane police responded to the Cardall situation in accordance with their training. Washington County Attorney Brock Belnap last year found the officers were justified in using a Taser on Cardall.
A legislative resolution passed earlier this year called for law enforcement agencies to put their officers through existing crisis training designed to improve officers' encounters with the mentally ill.
Tribune reporter Melinda Rogers contributed to this report.
What's next in Utah's Cardall case?
P A 10-day jury trial in a lawsuit filed by survivors of Brian Cardall is tentatively set to begin in U.S. District Court on Nov. 28 before Judge Clark Waddoups.
Other Utah deaths following stun gun deployments
December 2004 • Police used a Taser on an Orem man who nearly collided with four cars while driving erratically on U.S. Highway 189 near Heber City. After a fight with police, which involved two Taser shocks and pepper spray, the driver, Douglas Meldrum, 37, died. An autopsy attributed the man's death to heart failure caused by the scuffle and high concentrations of ephedrine in his blood.
April 2006 • Salt Lake City police used a Taser on Alvin Itula, 35, whom police mistakenly identified as a fugitive. As police tried to arrest Itula, a fight began and police shocked him at least four times with a Taser and used pepper spray and clubs. Itula died a short time later. His autopsy revealed high levels of cocaine and methamphetamine in his blood.