Taser (Associated Press)

What are Tasers?

They are hand-held weapons that deliver a jolt of electricity — up to 50,000 volts — from up to 10.6 metres away. The shot can penetrate up to five centimetres of clothing.

It stuns the target by causing an uncontrollable contraction of the muscle tissue. He/she is immobilized and falls to the ground — regardless of pain tolerance or mental focus.

TASER stands for Thomas A. Swift Electric Rifle, from the Tom Swift series of children's novels written in the early 20th century, including Tom Swift and his Electric Rifle. The real stars of the series of science-fiction novels were potential advances in technology.

Who makes them?

Arizona-based Taser International makes virtually all of the "stun guns" being used today. In fact, Taser is the brand name and the technical term for a stun gun, a conductive energy device, or CED.

Taser International says more than 11,000 law enforcement, correctional and military organizations, in 44 countries, use its devices. Of these agencies, more than 3,500 of them equip all of their patrol officers with Tasers. Since 1998, more than 260,000 Taser brand immobilizers have been sold to law enforcement agencies.

There are two main types of stun guns made by Taser, used by law-enforcement agencies:

• M26: a high-powered weapon marketed to police forces to stop "highly combative individuals." A burst of compressed nitrogen launches two small probes attached to the device by conductive wires. From as far as 10.6 metres, the device transmits electrical pulses through the wires to immobilize a person. Also has a laser sight for aiming.
• X26: A smaller model introduced in 2003. Launches two small probes as far as 10.6 metres.
• The company also makes a stun guns for personal use:
• C2: Smaller than its predecessors and comes in four colours. Launches two probes as far as 4.5 metres.
• X26C: Modelled after the X26, but formatted for personal use. Has a range of 4.5 metres.
• Advanced Taser M18/M18L - Modelled after the M26, and has a range of 4.5 metres.

In the United States, Tasers are not considered firearms and are legal for civilian use in most states. Some cities, counties and states do restrict — or ban — their use by people who are not police officers. The company will not ship its product outside the United States, unless the person placing the order holds a valid import/export permit.

In Canada, however, Tasers are a prohibited weapon. Only one company can import them into Canada under a special permit, and they can only sell the devices to law enforcement agencies, said RCMP Cpl. Greg Gillis, who trains police officers how to use Tasers. Each Taser sale is registered and tracked, much like a handgun, he said.

What are the benefits of stun guns?

Tasers are supposed to allow police officers to subdue violent individuals without killing them. A police officer can "take down" a threatening suspect without worrying that a stray bullet might kill or injure an innocent bystander.

"There's no question that there are certainly lots of documented examples in Canada where had we not had the Taser and had to respond with more traditional options, that it could have resulted in a higher level of force," said Cpl. Gillis. "For, example, the firearm. And with a firearm there are only two outcomes … it's going to be a permanent injury or a loss of life."

What are the drawbacks?

The company says there are none. Critics argue that there hasn't been enough research into the safety of stun guns. They point to the deaths since 2001 of more than 50 people in North America after Taser shocks.

On its website, the company states that "Independent medical and scientific experts have determined Taser devices to be among the safest use-of-force options available."

While there have been several accounts of deaths involving Tasers, the exact cause of death is often contentious.

In July 2005 for example, a Chicago medical examiner ruled that the death of a man in February 2005 was the result of being shot with a Taser by Chicago police. Media reports said it was the first time a death had been linked directly to a police stun gun, although the medical examiner said the victim also had a lot of methamphetamine in his system.

On Oct. 14, 2007, 40-year-old Robert Dziekanski of Pieszyce, Poland, died at Vancouver International Airport after being shocked with a Taser by police. Airport security called the RCMP for help after Dziekanski allegedly was pounding on windows and throwing chairs and computer equipment.

The Mounties speculated that he died from a rare condition called excited delirium, though the coroner's office has not concluded the cause of death. Excited delirium is described as an agitated state, when a person experiences an irregular heartbeat and suddenly dies. It can happen to psychiatric patients and people using drugs such as cocaine. But critics charge that excited delirium is not a valid medical term.

Dziekanski's death renewed calls for a moratorium on Taser use. The sentiment intensified when, less than a week later, a Montreal man died after being zapped by a Taser by police.

Quilem Registre, 38, was intoxicated when he was stopped by police on Oct. 14 for a traffic violation. Police say he became aggressive when questioned and officers were forced to use a Taser. He was sent to hospital in critical condition, where he died Oct. 17.

Registre was the 17th person to die from a stun-gun-related death in Canada.

The company notes that about 100,000 police officers have volunteered to take hits from Taser weapons — with no deaths.

What does the research say?

In 1989, a Canadian study found that stun guns induced heart attacks in pigs with pacemakers. Ten years later, an American study concluded that weapons delivering a jolt weaker than Tasers increased the risk of cardiac arrest in people with heart conditions.

But Steve Palmer of Canadian Police Research Centre — a partnership among the Canadian Association of Chiefs of Police, the RCMP, and the National Research Council Canada — said there have been several international studies that demonstrate their harmlessness.

"There is a growing body of knowledge out there that these devices are safe when used properly," said Palmer, the organization's executive director. "We don't speak often enough about the number of lives that have been saved, the number of people that are up and walking around today that might not have been had it not been for a Taser."

Figures compiled by the CPRC suggest that most mid-size police forces only use stun guns between 50 to 60 times a year, on average. They were only used 51 times in 2006 by police officers in Quebec.

What's the Canadian perspective?

Canadian police say Tasers have saved 4,000 lives since police forces started using them in this country in 1999.

Still, Staff Sgt. Peter Sherstan, of the RCMP's Emergency Response Team in Edmonton, says Tasers should not be considered non-lethal.

"The RCMP's position is that Tasers are a less-lethal alternative," Sherstan told CBC Radio. "There are still risks. There could be a situation where a person hit with a Taser shot could fall and hit his head. But we have to balance that out. We have several cases where if Tasers weren't present, guns would have been the alternative."

Amnesty International Canada has been calling for a suspension in the use of Tasers until studies can determine how they can be safely used. The organization repeated that call after two people died in one week after being shocked with a Taser by police in October 2007.

"Obviously police should be using non-lethal alternatives," Alex Neve, the organization's secretary general, said. "But the standards say those non-lethal alternatives should be fully investigated. We need to have a study, we need to understand what those risks are."

Beatrice Veaugrante, head of the human right's organization's Quebec branch, told Canadian Press that there has yet to be an independent study in Canada about the safety of Tasers.

Neve says tests on police and members of the military may have gone well, but he notes they're among the fittest people around and not likely to suffer adverse reactions to a Taser shot. Studies, he says, have suggested that people who abuse drugs or who have heart conditions could be at risk.

Amnesty International also worries that officers might be tempted to use weapons like Tasers too often if they believe they're not lethal. Sherstan argues that shouldn't be an issue if officers are properly trained in their use.

How many are in use within Canada's law enforcement agencies?

There aren't concrete numbers, but Cpl. Gillis estimates there are 2,000 to 3,000 available to RCMP officers across Canada.

When do police officers use Tasers? What are the rules of engagement?

Police do follow the police use of force framework, which outlines when certain approaches are warranted. But, an RCMP officer can use his or her own discretion to decide when to deploy a Taser, according to Cpl. Gillis.

"What we generally suggest is if it's a situation where O.C. spray, or pepper spray, would be appropriate for use, and that usually means I'm demonstrating some sort of combative or assault-like behaviour … that might be an appropriate choice for a Taser."

Const. George Schuurman, of the Toronto Police Service's public information department, also said there were no blanket guidelines. An officer would assess the situation based on their training, and use their judgment, he said.

Officers would also look at the environment, and if using pepper spray could possibly injure people nearby, or, for example, be sucked into the ventilation system and hurt innocent bystanders, Gillis said.

And, he added, there are three groups of people that pepper spray may fail to subdue: 1) people suffering from a mental health crisis; 2) people determined to charge/inflict harm; and 3) people under the influence of drugs or alcohol. The main mechanism of pepper spray, pain, may not stop these types of individuals from continuing combative behaviours, Gillis said. Since a Taser immobilizes them, it's the better option, he said.

"A general rule of thumb is maybe three times. But, it's like any other tool. If I spray you with [pepper] spray and it doesn't work, try a second application … but if you're confident that, 'Yup, I'm getting [pepper] spray all over,' and he's somebody that's working through it, then transition to something else. Go to a different technique."

As well, RCMP officers are required to report every time the Taser is used and must justify its application, Gillis said. Officers must also report an incident if the mention of a Taser — such as an officer saying, "I'm going to use a Taser" — causes an individual to calm down their behaviour, Gillis said.