Trevor Grimolfson, 38, died on Oct. 29, 2008, after he was shocked by a stun gun. (CBC)The mother of Trevor Grimolfson, the man who died after Edmonton police used a stun gun while arresting him in 2008, criticized Taser International in her opening address Monday at a fatality inquiry.

Beverly Grimolfson said she believes "police have been led like lambs" by Taser International. She said she plans to introduce research showing the danger of the stun guns.

Grimolfson, 58, is representing herself at the five-day inquiry because she can't afford a lawyer, and a provincial court judge turned down her application for funding to pay for one.

"I feel that there's a lot of questions that need to be asked," she said outside the courthouse, "I was not allowed any funding for a lawyer so I had to come and stick up for my son by myself."

Trevor Grimolfson, 38, died Oct. 29, 2008, after police tried to subdue him with a stun gun.

Beverly Grimolfson is representing herself at a fatality inquiry into her son's death in Edmonton this week. (CBC) He was high on drugs, rampaging through a pawnshop in Edmonton's west end. He died later in hospital. The cause of death was ruled “excited delirium due to the consequences of multiple drug toxicity.”

But Beverly Grimolfson believes her son would be alive if he had not been shocked by a Taser, she said.

"It's a story of power, profit and coverup," Grimolfson told the inquiry in an Edmonton courtroom.

The use of a Taser was a "personal, violent overreaction" to her son's behaviour, she said.

Grimolfson joined by Dziekanski's mother

Forensic pathologist Dr. Graeme Dowling testified Monday that Grimolfson had been in a state of excited delirium.

Blood tests showed he was on ecstasy, cocaine and ketamine.

Robert Dziekanski's mother, Zofia Cisowski, came to Edmonton to support Grimolfson at the fatality inquiry. (CBC) Excited delirium as a diagnosis is still controversial, and Dowling said he didn't know why certain people die from it.

If a person is shocked with a Taser, it could increase the level of adrenalin in their system, he suggested.

"It is my understanding that there was no observed effect of the Taser on Mr. Grimolfson," Dowling said.

Grimolfson was joined in the courtroom by the mother of Robert Dziekanski, whose son died after being shocked numerous times by police in the Vancouver airport.

"I am very frustrated because it's reminded me [of] my son struggling on the floor with his life," Zofia Cisowski said. Cisowski said she came to Edmonton to support Grimolfson.

Both women say will form a national group to ban the use of stun guns.

Before the inquiry, Grimolfson said police misled her about their investigation into her son’s death.

“They have never told me anything,” she said. “I feel that I have been lied to right from the beginning, lied about what kind of Tasers they were, lied about how many times he was Tasered, where he was Tasered.

“It's just been a nightmare. And now this is the only chance I have to get some sort of justice.”

Last year, the Alberta Serious Incident Response Team, which investigates any death involving police, cleared the officers of any wrongdoing during Grimolfson's arrest.

The judge may make recommendations on how to prevent similar deaths.

With files from The Canadian Press