It's "premature" to allow a man who killed a Toronto police officer with a snowplow into the community before doctors can figure out the nature of his mental illness, the Ontario government argued Monday in court.

Ontario's highest court is considering a Crown appeal of a review board decision to allow staff at a psychiatric hospital to escort Richard Kachkar on trips into the community.

Kachkar has been detained in a secure forensic ward at the Ontario Shores facility in Whitby, Ont., since he was found not criminally responsible for killing Sgt. Ryan Russell.

He is a "model patient," his lawyer said. Kachkar has not shown any active psychosis since then and he has been fully compliant with treatment and medication, his doctors report.

But there is still much uncertainty about Kachkar's condition, so allowing him into the community puts the public at "undue risk," Crown attorney Eric Siebenmorgen told a panel of judges at Ontario's Appeal Court.

"He appears to be doing well, but of course there is no further insight into what the diagnosis is," Siebenmorgen said. "Is it a mood disorder? Is it schizophrenia? Is it something else?"

Diagnosis still unclear

Three psychiatrists who assessed Kachkar for his trial could not settle on a diagnosis. Dr. Philip Klassen, who also testified at the Ontario Review Board hearing, said he could only label Kachkar as having a psychosis not otherwise specified. One of his current doctors has mused about Kachkar having bipolar disorder, Siebenmorgen said.

"(Until there is) a tentative working diagnosis...any situation that could potentially put Mr. Kachkar and the police in the community in contact, or I should say conflict, could have potentially serious and disastrous consequences."

The hospital has not yet actually allowed Kachkar into the community. His lawyers say he has been granted "off-ward" privileges more than 100 times, though all within hospital property.

If staff were to escort him into the community and Kachkar suddenly became unmanageable, the staff are not allowed to physically intervene, Siebenmorgen said. They would have to call police.

"Given the history, that's a dangerous situation to set up," Siebenmorgen said.

Kachkar's lawyer said the psychotic break that led to the death of Russell didn't come out of nowhere, rather he appeared to unravel over about two weeks, so hospital staff would be able to assess his condition before any outing.

Kachkar did try to seek help at a hospital, a walk-in clinic and from shelter staff, his lawyer Peter Copeland noted, and he did appear unwell to those who knew him in that two-week period.

Not difficult for staff to see signs

"It would not be difficult for hospital staff...to identify the signs of an onsent of a psychotic episode," Copeland said.

Kachkar's lawyer and the Crown appeared before the board last year with a joint recommendation for where Kachkar should be treated and what privileges he should be granted, including walking the grounds of the hospital while escorted.

The Crown's main issue on appeal is that the board went a step further than the joint recommendation and said Kachkar should also be able to enter the community while escorted. The board said its decision was consistent with its mandate to give the least onerous conditions while keeping public safety in mind.

The Appeal Court reserved its ruling, meaning it will be released whenever the judges reach a decision, likely in the near future.

The Crown is not appealing the not criminally responsible verdict, rather the review board's decision about Kachkar's hospital privileges.

NCR patients are subject to annual reviews, at which review board members hear evidence from doctors and assess whether they should be granted more privileges, have some revoked or, ultimately, grant the person an absolute discharge.

Kachkar's next review is scheduled for April 22.