The Truth in Sentencing Act, a centrepiece of the Conservative government's tough-on-crime strategy that limits judges' discretion over sentencing, came under fire in a Supreme Court of Canada hearing on Thursday.

The hearing involved two cases in which offenders received 1.5 times credit for time spent in pre-trial custody in recognition of the fact that, under little-known Canadian laws, jail time served after sentencing is nearly always reduced by one-third. However, the four-year-old act sets out a general rule that offenders get just one day credit for each day in jail before sentencing. Courts of Appeal in Ontario and Nova Scotia upheld the extra credit, leading to the Supreme Court hearing. (Read an explainer of the Conservatives' sentencing law)

It is just one front on which judges are pushing back against legislation that strives to limit their discretion: Across Canada, some judges have deemed mandatory minimum sentences unconstitutional, and others have refused to impose mandatory financial penalties on the indigent to pay for victim services.

Story continues below advertisement

Federal lawyer David Schermbrucker told the court the intent of the Truth in Sentencing Act is clear in its subtitle – "limiting credit for time spent in pre-sentencing custody."

Justice Rosalie Abella asked what happened to parity and proportionality in the Criminal Code's sentencing principles. "How does your interpretation fit with those principles? Or is it your argument that we ignore them?"

Mr. Schermbrucker replied that enhanced credit is a separate matter from sentencing.

Gregory Tweney, lawyer for the Ontario Attorney-General's ministry, which supports the sentencing law, drew a pointed response from Chief Justice Beverley McLachlin when he suggested jail terms of similar length for people found guilty of similar offences should not be at issue when judges give credit for pre-sentence custody.

"I'm looking for the authority for your proposition," Chief Justice McLachlin told him. "It's fundamental to justice that people get treated alike."

She said he was asking for offenders to be looked at in "a tiny little microcosm. It strikes me that's a very crabbed way of looking at sentencing. It doesn't accord with the way the public talks about sentencing: 'He got nine years, why did [someone else] get six?'"

Justice Thomas Cromwell asked why the government was not more direct if it wished to end a long-standing practice. The Truth in Sentencing Act says judges may give 1.5 times credit "if circumstances justify it," but does not spell out what they would be. Ottawa argues that under the law, all prisoners who spend time in pre-trial custody do not get extra credit for it in the automatic reductions of their sentences; it is not a departure from the norm, and therefore not deserving of extra credit. Mr. Schermbrucker, the federal lawyer, said the common-sense meaning of the law was clear.

Story continues below advertisement

Justices Marshall Rothstein and Richard Wagner asked lawyers who support the routine granting of 1.5 times credit if it was fair to inmates who, for example, were beaten in pre-trial custody, that they receive no more credit than almost all others.

Andrew Faith, a lawyer for the John Howard Society, which had intervenor status at the hearing, noted that the Truth in Sentencing Act explicitly denies extra credit to those held in custody because they have violated bail conditions before or because they have a criminal record. Those people are authors of their own detention, he said, but most others who are denied bail are the poor, homeless, mentally ill and aboriginals who lack the resources or connections to find someone to act as a surety, guaranteeing their bail.

"Why should the people who can't afford to make bail serve more time in custody than the people who can?" he said.

Paloma Aguilar, press secretary for Justice Minister Peter MacKay, said by e-mail that the law was meant to build confidence in the justice system. The court reserved judgment.