Expert tells inquiry Taser likely most significant factor in Dziekanski death

"... Several say the Taser played a part in Dziekanski's death, while others - mainly those paid by the weapon's manufacturer - told the B.C. inquiry it had no impact ..."

See Dr. Chambers' complete written opinion here.

May 14, 2009
The Canadian Press

VANCOUVER, B.C. — The multiple stuns from an RCMP Taser were likely the most significant factor in Robert Dziekanski's death, an epidemiologist told a public inquiry Thursday, adding to the litany of diverging medical opinions presented at the ongoing inquest.

Dziekanski died at Vancouver's airport in October 2007, after four RCMP officers were summoned to deal with the agitated man as he threw furniture around the arrivals area. Within seconds, an officer jolted him several times with the Taser.

A collection of experts from Canada and abroad have been called to testify at the inquiry.

Several say the Taser played a part in Dziekanski's death, while others - mainly those paid by the weapon's manufacturer - told the B.C. inquiry it had no impact.

The latest opinion came from Dr. Gordon Keith Chambers, a Vancouver-based epidemiologist who testified Thursday that the Taser stuns likely had the greatest impact in stopping Dziekanski's heart as he lay on the airport floor.

He also discounted much of the research that Taser relies upon to portray its weapon as safe.

Chambers submitted a report to the inquiry that said it appeared Dziekanski died of a fatal heart arrhythmia caused by the jolts from the Taser and the stress of being restrained by police.

But he said Dziekanski's response to the stun gun - his screaming and struggling - was much stronger than when he was pinned to the floor, suggesting the Taser had a much larger effect.

"So while both most likely contributed to the death of Mr. Dziekanski, in my opinion the act of Tasering ... contributed more to his stress response and subsequent demise than physical restraint," Chambers wrote in his report.

He also said Dziekanski's deteriorating condition after he was handcuffed - he quickly went unconscious and within seconds started turning blue - suggests Dziekanski died much sooner than police have said.

Chambers said the only video evidence of anyone checking Dziekanski's pulse - a security guard feeling the man's neck for a few seconds - would be inadequate to determine whether he had a heartbeat.

An autopsy concluded Dziekanski died of "sudden death during restraint," a little-understood term that has been used when no physiological cause of death can be found.

Chambers said the witness video, the results of an autopsy and Dziekanski's medical history can be used to rule out several other possible causes of death, such as heart disease, alcohol or drug impairment or mental illness.

He said in absence of any other potential cause, the only conclusion left to be drawn is that Dziekanski's encounter with police, and most significantly the use of the Taser, caused his heart to stop.

A lawyer for Taser International, which has long insisted the weapon cannot kill, spent hours challenging Chambers' opinions in a heated cross-examination.

David Neave cited several studies that he said showed the Taser is safe and hasn't been linked to fatal heart arrhythmias.

But Chambers called Neave's examples, several conducted by researchers with links to Taser, "failed" studies that drew conclusions not supported by the data.

He said the sample sizes were too small, the participants were not randomized, and information was often collected by police officers or other people who use the weapons, rather than by independent experts using standard research methods.

"What's missing in these studies is that, when we are looking at rare events, to actually figure out what's going on, you need large sample sizes," he said.

"These small studies ... are probably not large enough to support the claims that are being made."

Chambers did agree that it would be rare for a Taser to cause a death - rare enough that a sample of a few hundred people wouldn't reveal the risk.