OTTAWA–The RCMP is scrutinizing its stun guns in response to a new analysis that found some Tasers pack more of a shock than the manufacturer promises, raising questions about their safety.

A scientific review commissioned by the CBC and French-language Radio-Canada concluded that four out of 41 guns tested actually discharged more electrical current than Taser International says is possible.

In some of the test firings the police weapons delivered 50 per cent more current.

The examination was conducted by an American lab, National Technical Systems, using X26 model Tasers from seven police departments in the U.S. eager to see how the guns fared. The police services agreed to participate on condition of anonymity.

University of Montreal engineer Pierre Savard, who designed the testing procedure based on Taser International's own guidelines, found the results troubling.

Savard studies heart rhythms and how they are affected by electrical stimulation. He says since police officers are trained to aim the Taser at the chest for the best chance of a hit, the increase in current could be highly dangerous under certain circumstances.

"When you combine an increased current intensity with a dart that falls right over the heart for somebody who has cardio- vascular disease or other conditions, such as using drugs for example, it can all add up to a fatal issue."

Two other experts consulted by CBC, engineer Stephane Masse of the Toronto University Health Network, and engineer Roger Barr at Duke University in North Carolina, agreed with Savard's lab analysis.

The Taser X26 is widely used by the RCMP and many other police forces across North America. The four Tasers that malfunctioned were amongst the oldest, manufactured prior to 2005.

Savard wants police to stop using these older guns altogether until they have been tested to find out why so many stray from the manufacturer's specifications.

In a written response to the CBC, Taser International acknowledges the results show four of the devices displayed anomalies.

Magne Nerheim, Taser vice-president of research and development, suggests because the unusual behaviour appears in the first moments of firing it is a sign that the guns may not have been spark-tested regularly as Taser recommends to police officers.

But a Taser International testing protocol obtained by CBC makes no mention of a spark-test.

Nerheim also says the results aren't "relevant from a medical safety perspective."

In a statement, the company added, "The results from the testing are generally consistent with the specifications provided by Taser International and which would be expected from such tests."

Savard and the other scientists say they stand by their analysis.

CBC and Radio-Canada say their study is the largest independent lab test of Tasers to date.

Savard agreed to take part out of concern no one was verifying the claims of Arizona-based Taser International.

Loading... Loading... Loading... Loading... Loading... Loading...

At a recent policing conference, RCMP Commissioner William Elliott told the CBC that in response to the broadcaster's findings the force was pulling Tasers out of its inventory for examination. ``We are gathering up samples from each of our divisions, every province and every territory, and we will have them tested."

On Thursday, the RCMP said preliminary findings indicated the Tasers tested at an Ottawa lab were operating within the manufacturer's specifications. However, the Mounties did not share details of its tests with the CBC.

The force is awaiting final lab results.

A report commissioned by the RCMP earlier this year said national standards, more resources and better co-ordination are needed to ensure officers are properly trained to use Taser stun guns.

The report said the Mounties did not get enough input from medical and mental health experts about the weapon's impact on people.

More than 20 people in Canada have died after being hit with a Taser.

Taser International insists the devices cannot be blamed for deaths.

However, medical officials have cited the guns as contributing factors in some cases.

Amnesty International Canada has repeatedly urged a temporary halt to Taser use pending an independent, in-depth study of potential risks.

RCMP complaints commission chairman Paul Kennedy has called on the force to restrict Taser use to major threats where a person is combative or risks serious harm to themselves or others.

Kennedy wants tighter controls on a powerful and painful weapon the Mounties have drawn from their holsters more than 4,000 times since its introduction in 2001.

Read more about: