TORONTO -- A mentally disturbed man who mowed down and killed a Toronto police officer with a snow plow will be sent to a psychiatric hospital instead of prison after a jury found that his illness was to blame.

Richard Kachkar, 46, showed no emotion Wednesday as a jury found him not criminally responsible in the death of Sgt. Ryan Russell, 35.

The verdict was clearly deeply unsatisfying for Russell's family, including his widow Christine, who hoped for a first-degree murder conviction and its accompanying life sentence.

"I imagine like most people that everyone is very disappointed, that we're heartbroken," Christine Russell said outside court, standing beside the head of the Toronto police union.

"I believe that Ryan deserved a lot better than this...There is no healing. There's no closure. There's no end."

The jury's verdict, reached in the third day of deliberations, means they believed Kachkar couldn't appreciate what he was doing when he drove the 5,050-kilogram plow at Russell, knocking him down, fracturing his skull and leaving him dying in the snow.

Now that he has been declared not criminally responsible, the Ontario Review Board will assess him and he will be sent to be treated at a psychiatric facility. After the initial assessment, he will be subject to annual reviews.

Only when the board decides he is not a significant threat to public safety will he be fully discharged.

Christine Russell said she will remain in limbo as she fights at each annual hearing to keep Kachkar under care. Her four-year-old son Nolan is worried that the man who killed his father will hurt him too, she said.

After the funeral, Nolan, then two years old, asked where his daddy was, Russell said. Now he is starting to understand.

"One night he was very upset," she said in a victim impact statement. "I asked him why he was crying and he said, 'Because daddy can't come down from heaven and read to me.' Just recently he told me, 'I'm not happy because I want daddy to come home."'

Kachkar was assessed for the trial by three prominent forensic psychiatrists, including one who was chosen by the Crown, each of whom found that the drifter from St. Catharines, Ont., was psychotic when he killed Russell, that his mind had broken from reality.

Now that he is able to grasp what he did, Kachkar "feels terrible," his lawyer Bob Richardson said.

Some people may not agree with the verdict, Richardson acknowledged outside court, but noted it doesn't mean his client will just walk free.

"I think before people criticize something they should take the time to perhaps try and understand it," he said.

"It's not a get-out-of-jail-free card. It's a recognition that someone is very, very sick and needs to be treated...It doesn't mean that they're not accountable. He's accountable because he's going into the hospital system."

Though all three forensic psychiatrists agreed that psychosis had taken hold of Kachkar's mind, they were unsure exactly how to categorize his mental illness and they all struggled with a specific diagnosis.

Dr. Philip Klassen said if he had to offer a diagnosis it would be either an unspecified psychotic disorder or possibly schizophrenia.

He suggested that Kachkar suffered for several years from a "low-grade" mental illness with periodic spikes, such as in 2006 when he woke up in the middle of the night screaming that he was possessed by the devil and slapped his wife.

It appears to have spiked again before Kachkar killed Russell, Klassen testified at trial.

Early on the morning on Jan. 12, 2011, Kachkar fled a Toronto shelter barefoot, running out into the snowy streets and stole a truck with a plow attached from two landscapers who had stopped for a coffee.

He then drove the plow around the city for two hours, crashing into a luxury car dealership, hitting vehicles and crossing into oncoming traffic. He killed Russell at about the halfway point when the officer tried to stop him.

Witnesses heard Kachkar yelling at various times about the Taliban, Chinese technology and that "it's all a Russian video game."

He was finally stopped by emergency task force officers who Tasered him and shot him in order to arrest him.

As paramedics tended to his gunshot wounds he worried they were trying to poison him or put microchips in his body, court heard.

Toronto Police Chief Bill Blair said he accepts the verdict in what he said was a difficult case.

"There's never going to be any sense of satisfaction from any outcome," Blair said at police headquarters.

"We lost a man and a family lost someone very, very dear to them...The tragedy of that is not relieved by this verdict but we understand the nature of the verdict. It was a tough case."

Russell's father, Glenn Russell, stared straight at Kachkar as he delivered a victim impact statement about the irreparable damage to his family.

"Each day is a challenge to get through. There isn't an hour of the day that goes by that I don't think of Ryan," he said.

"You killed a son and a brother who was much loved. You killed a man who was well respected as a person and as a police officer. You killed a loving husband and most importantly you killed a father who was the centre of his young son's universe."

Christine Russell said she supports legislation proposed by the Conservative government that would see stricter conditions put on people designated as high-risk not criminally responsible. It would also revoke the annual reviews in favour of holding them only once every three years.

In Ottawa, Justice Minister Rob Nicholson reacted to the verdict by lobbying for the new legislation.

"We have a bill before parliament that puts the protection of the public as paramount consideration...so I hope that gets passed very quickly."

The lead Toronto police detective in the case, Mary Vruna, told reporters it was the most difficult one she's ever worked on but wouldn't comment when asked if she thought the evidence supported the verdict.

"It doesn't matter what decision they would've come up with, whether it was not criminally responsible or a conviction for murder, it doesn't change the loss that the Russell family, Ryan Russell's friends and Ryan's wife and son will carry with them for the rest of their lives," she said.