In the annals of true Canadian crime, the killing of Tim McLean ranks as one of the most horrifying. A 23-year-old minding his own business on a bus from Edmonton to Winnipeg was attacked, stabbed and decapitated by fellow passenger Vincent Li six years ago.

Seemingly, it's a crime that would have put Li away for life in a federal penitentiary, but he was found not criminally responsible by reason of mental illness, in this case schizophrenia, and sent to a provincial psychiatric hospital.

Now he's been granted the freedom to go out and about on his own — a decision by independent medical and legal authorities that has both the federal government and Manitoba, where Li is housed, sniping at each other.

At his trial, Li was found by a judge to be "not criminally responsible," meaning he either had no understanding of what he was doing, or he did not realize what the result of his actions would be.

That finding left his future in the hands of Manitoba's Criminal Code Review Board.

The board takes the advice of a team of psychiatric and legal experts who determine Li's treatment and assess his progress; then it decides whether or not to approve the team's recommendations.

Each year the review board has granted Li more privileges, given that he has responded well to treatment and medication.

Last week it set off a firestorm by approving new conditions that allow Li to have unescorted day-trips (starting with 30 minutes and progressing to full days), unsupervised group outings and transfer from a secure wing of the hospital to an unlocked ward.

The Selkirk Mental Health Centre, where he has been housed, would not confirm whether he has been on his own yet, citing patient privacy.

'Shocking'

Political reaction to the review panel's decision was swift and impugning.

Federal Justice Minister Peter MacKay called the decision "shocking." Manitoba Premier Greg Selinger also came out opposed to the unescorted day passes.

Justice Minister Peter MacKay wants Manitoba to appeal the review board ruling in the Li case. Manitoba says it can't do that as the board is bound by federal law, which is in the process of being changed. (Fred Chartrand / Canadian Press)

And Heritage Minister Shelley Glover, Manitoba's senior federal cabinet minister, asked the province to appeal the review board decision.

A spokesman said the provincial attorney general can't appeal the decision as the independent Crown prosecutor had supported the Li recommendations.

Not surprisingly, Tim McLean's mother is also disappointed with the ruling and calls it a systemic failure at all levels. "I ultimately do not believe that when you take a life, you have the right to freedom any longer," said Carol de Delley.

One of her biggest concerns is that Li could reoffend, "...and if he does, what will happen then?"

'High-risk' offenders

"The reality is, most of our prisons and jails are filled with people with mental illness," says Toronto lawyer Sheila C. MacKinnon, who specializes in youth law and argues strongly for a full rethink of the whole criminal mental health system.

"People who take their medication can be fine and productive members of society, but there are many who don't have that insight, who don't have help, and they end up getting into trouble.

"That doesn't help society at all and puts everybody more at risk."

At this point, however, Ottawa's solution is for legislation that would create a new high-risk designation to keep certain mentally-ill offenders locked away for life — whether or not they are rehabilitated.

Bill C-54 recasts the definition of what it means to be a "significant threat to public safety," which is something a provincial review board usually decides.

Carol de Delley, the mother of Tim McLean, the young man murdered by Vincent Li, feels Li should be spending the rest of his life behind bars. (CBC)

It would automatically designate someone claiming a NCR defence "high- risk" in cases where the "acts were of such a brutal nature as to indicate a risk of grave harm to the public."

A high-risk offender would not be allowed out for community visits except under very narrow circumstances and only with a mandatory public safety plan in place.

Review boards have a mandate to put public safety first, but they approach it with a goal of rehabilitating patients to reintegrate them into society.

Critics of C-54 say a one-size-fits-all approach runs the risk of denying liberty to those who do make progress, as Vincent Li is said to have done, and could run up against the Constitution's ban on cruel and unusual punishment.

'Warehousing'

Herbert Cheong, diagnosed with schizophrenia, wasn't on his medication the day he pushed 23-year-old Charlene Minkowski into an oncoming subway train in 1997. She died nine hours later.

My then five-year old son and I saw it happen. We were standing next to the TTC driver when the train barrelled into the station.

Moments later there was a commotion on the platform near the point of impact. Witnesses were screaming and swearing at Cheong who stood motionless, calmly staring ahead through thick black-framed glasses held together by white tape.

A drifter with a 20-year history of mental illness, Cheong was convicted of second-degree murder and sentenced to prison with no chance of parole for 15 years.

Mental health treatment is voluntary in federal penitentiaries. If Cheong is ever released, he will be monitored by the Parole Board of Canada, but may not be rehabilitated when he re-enters a community.

Studies on recidivism rates for murderers show that the longer they are behind bars, the more likely they are to re-offend. And that rate is slightly higher for murderers who killed a stranger.

As MacKinnon notes, "one day their sentence is up, and then what? There's no support."

Canada has one of the highest incarceration rates in the West, and the cost of keeping prisoners behind bars has risen dramatically over the past decade. It is now about $114,000 a year for each inmate.

Critics say that warehousing offenders is expensive and is not structured to prepare them for life outside of prison walls.

Meanwhile, the chair of the Ontario Review Board, Justice Richard Schneider, has said that 93 per cent of NCR patients do not re-offend, and treatment of mental illness is effective.

It's an impressive success rate, but cold comfort for those who might find themselves living alongside the other seven per cent.

Risk appraisal

A less impressive rate was found by research psychologist Grant Harris, who says that approximately 25 per cent of NCR offenders committed an "officially detected" violent criminal act within 20 years after being released.

But he and his research collaborators in Penetanguishene, Ont., have developed an actuarial tool called the Violence Risk Appraisal Guide, to try to better assess the risk of criminal violence after any type of violent offender is released into the community, either from a prison or mental health facility.

There is evidence that statistical prediction may be more accurate than clinical judgment in decision-making situations. VRAG uses 12 variables that give violent offenders an objective numerical score: the higher the score, the greater the risk, and vice versa.

"We don't have infinite resources for patients, and we want to reserve custody and other intensive services for those of highest risk," Harris says. "Generally, people with lower scores could be managed in a less-secure setting."

VRAG has been tested or is used in every province, the U.S. and more than half a dozen European countries, and has a track record of predicting the overall number, severity, and imminence of violent recidivism, as well as other outcomes.

Canada's criminal justice is often caught in a tug-of-war between the responsibility of the courts to protect constitutional values and the obligation of legislators to shape public policy around things like the fear of violent offenders.

Bill C-54 passed the House of Commons in July 2013, and is headed for debate in the Senate.