Canada's top court will consider today whether judges have the right to undercut the will of Parliament by exempting certain convicts from the mandatory minimum prison terms required under the Criminal Code.

The issue before the Supreme Court of Canada is of equal interest to the Harper government, which is trying to toughen minimum sentencing rules for gun crimes, and for criminal defence lawyers, who have tried to find ways around them.

The case at the heart of today's hearing involves Michael Ferguson, a former Alberta RCMP officer convicted of shooting and killing a man he had taken into custody.

Mr. Ferguson was an experienced officer in October 1999 when he was dispatched during an overnight shift to answer a hit-and-run complaint called in by Darren Varley, a popular 26-year-old trucker from Pincher Creek, Alta.

Mr. Ferguson found Mr. Varley at the hospital, drunk and agitated. The two men got into a scuffle; the Mountie put him in handcuffs and took him to the RCMP detachment to spend the night there for public intoxication.

But when Mr. Ferguson tried to put Mr. Varley into a cell, another scuffle ensued. Mr. Varley pulled the officer's bulletproof vest over his head and grabbed his gun, pulling it halfway out of its holster.

Mr. Ferguson regained control of his handgun and shot Mr. Varley twice, first in the abdomen and then in the head, killing him.

After two mistrials following hung juries, a third jury ruled his first shot was justified as self-defence, but his second shot was not. Mr. Ferguson was convicted of manslaughter.

As with any manslaughter case involving a firearm, Mr. Ferguson faced a mandatory minimum sentence of four years in prison.

Because of the circumstances of the case, including the potential that Mr. Ferguson, as a former police officer, faced safety risks in prison, the judge granted him a "constitutional exemption." The judge found a four-year sentence would violate his Charter guarantees against exposure to "cruel and unusual punishment," and handed him instead a two-year conditional sentence, to be served under house arrest.

In a 2-1 decision, Alberta's Court of Appeal overturned the decision, saying the judge had no right to grant an exemption from a mandatory prison term.

Mr. Ferguson, although he has since been paroled, is now appealing that ruling at the Supreme Court.

At the heart of his case is the controversial question of mandatory minimum prison terms for gun crimes, and exemptions from those terms that a person might request on constitutional grounds. Critics say mandatory minimums remove the ability of judges to use their discretion in choosing less onerous options, such as conditional sentences, for some individuals.

The Harper government wants to harden this feature of the law, raising the mandatory prison terms for a host of gun crimes in its new "tackling violent crime" legislation, now before Parliament.

Criminal lawyers have tried for years to get around mandatory minimums by seeking constitutional exemptions for their clients. The result has been a handful of conflicting rulings across the country about the validity of exemptions.

© The Ottawa Citizen 2007