Federal New Democrat MP and justice critic Françoise Boivin is warning of growing tensions between the federal government and the courts, following a series of rulings that saw fit to deem the government's tough-on-crime agenda unconstitutional, four years after the legislation was first passed into law.

The Conservatives passed their first omnibus crime Bill C-2 – the Tackling Violent Crime Act – in 2008, effectively making changes to Canada's criminal code in an effort to "protect Canadians against those who commit serious and violent crimes."

In an interview with CBC's Alison Crawford, who was on assignment for CBC Radio's The House, Boivin said the Conservatives are "pitting the judicial against the legislative" and should instead reflect on the message the courts are sending them.

On Tuesday, Ontario Superior Court Judge Alan Bryant struck down a section of the Criminal Code, introduced in 2008, dealing with dangerous offenders.

"A breach of an individual's [charter] rights cannot be justified or condoned in a free and democratic society because the class of affected individuals is small," Bryant concluded.

The Crown had no evidence showing that the reverse onus was necessary to make sure the most dangerous offenders are designated as such, Bryant wrote.

Roland Hill, the man at the centre of this constitutional challenge, was convicted in 2000 of a sexual assault and in 2004 of assault causing bodily harm.

In the case now before the courts, Hill pleaded guilty to two counts of what Bryant called a "horrible" assault on a "defenceless young woman."

Bryant found that the reverse onus violates the charter, but that the Crown proved Hill was a dangerous offender through the traditional method.

But Carissima Mathen, an associate professor of law at the University of Ottawa, told Crawford the government should have seen this coming.

"Any time you use a reverse onus, you are fundamentally changing the normal way that the criminal law works where the government has to prove every part of a crime beyond a reasonable doubt. And a reverse onus gets away from that fundamental principle," Mathen said.

The dangerous offender reverse onus was part of the government's 2008 bill, which increased penalties in a number of areas, including gun control, drunk driving and the age of consent.

Mandatory minimum sentences

Kerry-Lynne Findlay, the parliamentary secretary to the Minister of Justice, told Crawford there was good reason for bringing in those changes which included mandatory minimum sentences.

"There is quite a difference in the sentencing outcomes, depending on the province or territory the particular case may happen to have been heard in. The other reason is to send a strong message that we are standing up for victims of crime and the most vulnerable in society and to make criminals more accountable for their actions," Findlay said.

But James Chadwick, a retired Superior Court judge, told Crawford sentencing is one of, if not the hardest aspects of being a judge.

When asked if mandatory minimum sentences would make a judge's job easier, Chadwick said "well, I guess it makes it easier for throwing the key away."

The ruling comes on the heels of two other instances during which judges in Ontario have struck down two mandatory minimum firearm penalties from the same "Tackling Violent Crime Act" omnibus law.

In July, an Ontario Court judge struck down a three-year firearm trafficking mandatory minimum sentence in the case of a crack dealer who offered to sell an undercover police officer a gun.

Justice Paul Bellefontaine ruled that Christopher Lewis should not have to face the mandatory minimum sentence of three years in jail for firearms trafficking.

He gave Lewis one year in jail for the firearms offence — although he also gave him an extra two years for other drug-related offences.

In February, Ontario Superior Court Judge Anne Molloy struck down a three-year minimum sentence for a first offence of illegally possessing a loaded gun.

At the centre of the case was Leroy Smickle, who was caught taking a webcam photo of himself while holding a gun.

Jeff Hershberg, a criminal lawyer, who represented Smickle, told Crawford his client "has no criminal record, a good work history, and is really a contributing member of society."

All eyes will now be on Bill C-10, the second omnibus crime bill the Conservatives passed in March, which included new mandatory minimum sentences for drug offences.

"I would be absolutely shocked if sometime in the very near future we do not see a challenge and a striking down of the mandatory minimums for the few marijuana plants that may be found in someone's home," said Hershberg.

All cases are expected to be appealed to higher courts.

With files from CBC's Alison Crawford and The Canadian Press