VANCOUVER - A Polish immigrant who died at Vancouver airport last year after being jolted five times by an RCMP Taser was a panicked alcoholic possibly in a state of delirium at the time, according to a review by Crown prosecutors.

Robert Dziekanski's death was not directly caused by the Taser jolts but they were one of several contributing factors, along with heart disease, alcohol withdrawal, the stress of being restrained and a decreased ability to breathe due to an officer kneeling on him, said Stan Lowe, spokesman for the B.C. Criminal Justice Branch.

Autopsy results revealed for the first time Friday found Dziekanski, 40, died because his heart stopped.

A forensic pathologist classified it as "sudden death following restraint," Lowe said, a cause of death that predates the use of Tasers.

The four Mounties who confronted Dziekanski won't face charges in his Oct. 14, 2007, death, Lowe announced.

"There is a substantial body of independent evidence which supports that the officers in question were lawfully engaged in their duties when they encountered Mr. Dziekanski and the force they used to subdue and restrain him was reasonable and necessary in all the circumstances," Lowe told reporters.

He said the evidence "falls markedly short" of justifying charges.

Lowe said a use-of-force expert from another police department concluded the officers followed RCMP policy on the use of force.

But while they're not criminally culpable, their actions played a part in the death, Lowe said.

Reaction of disappointment and anger

The decision not to charge police angered Dziekanski's mother, Zophia Cisowski.

"I'm angry, I'm mad, I'm disappointed," she said from her home in Kamloops, B.C. "They should criminally charge, of course. But they made the decision (and) I was expecting that."

She accused RCMP of covering up the truth of her son's death.

Cisowski, who said she has not worked and has been on medication since her son's death, planned to consult with her lawyer on whether to file a lawsuit against the RCMP.

"We have to think about what is the best for me, then we will do something, but I can't say anything," said Cisowski, who moved to Canada in 1999.

RCMP Supt. Wayne Rideout, who led the integrated police investigation team that looked at Dziekanski's death, saw the Crown decision as a vindication of the officers' actions.

"The investigation has revealed and shown, through the use of external, independent police department use-of-force experts, that their use and application of force was appropriate, it was lawful and it was within policy," he said. "The Crown counsel has now come back and said the same thing."

Nearly hysterical before flying

Police interviews with Dziekanski's friends in Poland revealed a man apprehensive about leaving and afraid of flying. He'd cancelled one flight and was forced to reschedule, Lowe said, and was nearly hysterical before boarding the plane.

Dziekanski, who did not speak English, arrived in Vancouver on the afternoon of Oct. 13, 2007, after a 21-hour journey.

He then wandered around the airport for up to 10 hours.

His mother had incorrectly told him she would meet him by the baggage carousels, which are actually behind a security barrier. Cisowski, told her son was not in the terminal, returned to her home in Kamloops.

Dziekanski finally cleared customs after midnight Oct. 14 and made it into the public area just before 1 a.m., 30 hours after leaving Poland.

Airport and border services officials described him as pale, nervous, confused, frustrated and sweating profusely, Lowe said.

Police and airport security staff were called after Dziekanski began to throw furniture around.

The Mounties arrived around 1:25 a.m., advised they'd be dealing with a violent, intoxicated man.

Dziekanski appeared to calm down at first, said Lowe, but then grabbed a stapler from a counter and held it out.

One officer shot Taser probes at Dziekanski and tried to zap him three times but Lowe said it malfunctioned because one of the probes did not make contact.

Dziekanski still hit the floor and continued to struggle while three officers tried to handcuff him, Lowe said. He was stunned twice more in "push stun mode" but continued to resist even as one officer knelt on his shoulder and neck area.

Once handcuffed, Dziekanski lost consciousness. Officers checked his pulse and breathing periodically and they were normal "in the circumstances," Lowe said.

However, firefighters and paramedics found no pulse. Dziekanski's heart had stopped.

Dziekanski's last moments were captured on a bystander's video, which has been seen around the world on TV and the Internet.

Worldwide outrage following death

Aware of the outrage sparked by the video, Lowe pleaded with the public to withhold judgment until a public inquiry is complete.

Despite the fact police were warned Dziekanski was intoxicated, an autopsy found no trace of drugs or alcohol. It did find evidence of chronic alcohol abuse.

But Cisowski rejected that conclusion.

"I know my son the best," she said. "I was in Poland in 2007 and I spent almost two months with him. He never asked me about even beer or something."

Medical experts in addiction and alcohol-related disease found his behaviour consistent with "the medical syndrome of delirium," Lowe said.

"The onset of the delirium could be explained by a number of factors including alcohol withdrawal, lack of sleep, dehydration and a high degree of anxiety," he said.

"Excited delirium"

The Crown was careful not to say Dziekanski suffered from "excited delirium," a term often used in connection with Taser-related deaths.

A report on Taser use commissioned by the RCMP last fall condemned the term, saying it is not a recognized medical diagnosis.

The charge decision clears the way for a public inquiry into the death to begin Jan. 19. RCMP had said the officers would not testify at the inquiry if they were facing charges.

RCMP Assistant Commissioner Al MacIntyre said Friday they will be involved in the inquiry.

"There is obviously a lot of emotion around this issue," MacIntyre said of Taser use.

"We do not believe, however, that this is a sound basis for making policy. Rather, decisions must be based on facts and scientific data."

He said RCMP have already made changes in the way Tasers are used, restricting use to cases involving public safety, and use-of-force rules have also been enhanced.

And he said older Taser models are being tested, although the unit used on Dziekanski was found to be working properly.

But he said none of those measures would have changed the outcome of Dziekanski's confrontation with police.

Of the four officers involved in the incident, one remains on duty in British Columbia, two have transferred to eastern Canada and a fourth is off duty awaiting trial on a charge of impaired driving causing death. Their identities have not been released.