Who decides where criminals like Paul Bernardo serve their sentences in Canada?

Revelations about who knew what about serial killer and rapist Paul Bernardo's transfer to a medium-security prison have many people questioning how the decision was made.

The subsequent public outcry and calls from the Conservative Party for federal Public Safety Minister Marco Mendicino's resignation have also raised the issue of who has the authority to make decisions about prison transfers — and who has the authority to overturn them.

Here's a look at that process, as well as what life would look like for Bernardo in a medium-security prison.

There are generally three levels of prisons in Canada: maximum, medium and minimum security. According to the Corrections and Conditional Release Act, when an inmate enters the system, Correctional Service Canada (CSC) assigns them a security classification based on the severity of the offence, history, physical and mental state and potential for violent behaviour.

The process also takes into account the risk of escape, need for supervision and risk to public safety. A review is required every two years, the CSC said in a statement. 

"We don't have sentences that confine people to maximum security for all of their sentences," said John Conroy, a British Columbia lawyer who wrote the book Canadian Prison Law. "And I would argue that type of a sentence would be counterproductive. It makes people worse if you give them no hope whatsoever."

Inmates look for opportunities to do what's called "cascading down" through the system to gain access to less restrictive environments and more programming, and to demonstrate that they can reintegrate into society.

"The parole board is very interested in your chances of success in the community," said Howard Sapers, a consultant and Canada's former correctional investigator.

"And your chances of success in the community are much greater if you've demonstrated that you're able to cascade down the security ladder and live and survive and be safe in increasingly less restrictive forms of custody."

Conroy said Bernardo, who was incarcerated at Millhaven Institution near Kingston, Ont., would have worked with a parole officer, manager of intervention and case management team to be considered for a transfer.

In addition to the reasons for judgment and victim impact statements, his behaviour in maximum security and any record of disciplinary offences would have been considered. The wardens of both institutions must also agree, he said.

Bernardo, 58, is serving a life sentence after being convicted in 1995 of the kidnapping, aggravated sexual assault and first-degree murder of two teenaged girls, and he was declared a dangerous offender. He's been transferred to La Macaza Institution, a medium-security prison in the Laurentians region of Quebec.

Crown attorneys who seek the designation must prove there is a high risk the individual in question will commit more violence or sexual offences.

A special process governs dangerous offenders who want to move into minimum-security prisons, which are not generally surrounded by fences. The chance of Bernardo being approved for a transfer to a minimum-security prison in the future is slim, Conroy said.