What was hailed as the best new tool on a police officer's belt has wound up in court after a number of complaints over its safety.
Makers of the Taser stun gun are having to defend the device - and the claims they made about its health risks - in the first such case to make it to trial. The lawsuit contends that a shock by the stun gun in 2002 ended the career of a sheriff's deputy in Maricopa County, Ariz.
It is the first of some 35 personal-injury, wrongful-death, or excessive-use-of-force lawsuits that have been filed against Taser International. Executives at the company in Scottsdale, Ariz., have vowed to fight them all in court, saying studies show their product is safe and does not cause serious injury or death.
In fact, earlier this month, Taser announced that use of its stun gun had saved an estimated 9,000 lives because police did not have to reach for a gun.
But a growing number of coroners across the country have cited Tasers as a contributing factor in accidental deaths. These and other questions about their safety have led some police departments to ban their use. They've also prompted an inquiry by the US Securities and Exchange Commission into claims the company has made about safety studies. In addition, the company's stock - formerly one of the market's best performers - has plunged.
Resembling a small pistol, the stun guns use nitrogen cartridges to propel darts into the body, delivering a 50,000-volt shock. Lasting several seconds, the shock immobilizes a person, thereby allowing officers to take control of the situation.
Police agencies began buying the stun guns in large quantities in 1999 and again in 2003 when the company reduced the product's size and weight. They are now used in more than 8,000 law-enforcement agencies across the country and are spreading into the US military.
They were initially well received by police departments that were looking for ways to reduce the number of fatal shootings by officers. Some indeed began to see dramatic declines after introducing the stun guns.
But Amnesty International is one group calling for a moratorium on Taser use until independent tests can be done to determine their safety. So far, the organization has counted 129 people who have died after being shot by a stun gun since June 2001.
"We concede that the development of nonlethal weapons saves lives and reduces injuries," says Ed Jackson of Amnesty International. "But independent studies have never been done to determine the potential harms posed by Taser technology. And we should not be using the public as guinea pigs."
The list of those who claim death or serious injury after experiencing the shock does not just include those subdued by law-enforcement officials. The largest group to experience Taser shocks is actually the police themselves. Many departments - including the Maricopa County Sheriff's Office - required officers to experience the shock before being allowed to use the gun. The Maricopa County Sheriff's Office and many others have abolished that rule.
From the witness stand in Maricopa County Superior Court, former Sheriff's Deputy Samuel Powers told the jury that he would never have agreed to be shocked during training if he knew the potential dangers. Doctors are expected to testify that he fractured his back during the incident.
His lawyer, John Dillingham, claims the company rushed the Taser to market without sufficient testing and deceived clients with misleading studies. Taser's lawyers claim Mr. Powers had osteoporosis and previously experienced back problems.
"Even if [Powers] knew he had osteoporosis, it made no difference because Taser failed to have any warning of any kind of the risks," said Mr. Dillingham in his opening statements last week.
Experts say the outcome of the trial, expected to last two weeks, could affect the strength of the company. But already, rival stun-gun makers are beginning to surface.
On Oct. 10, Stinger Systems announced it was beginning to sell its own stun gun to law-enforcement agencies in the US and abroad. The Florida-based company claims its device has a lower level of electrical output, making it safer but just as effective.
• The Associated Press contributed to this report.