While Norwegian Anders Behring Breivik has been deemed insane by a panel of psychiatrists, meaning he likely won't face time behind prison bars, the confessed mass killer may have faced a different fate in Canada.

"It's entirely possible," Prof. Roy O'Shaughnessy, head of the forensic psychiatry program at the University of British Columbia, told CBC News. "This would have been in a court of law and would have been subjected to an extremely vigorous cross-examination."

A psychiatric evaluation ordered by an Oslo court found that Breivik is not mentally fit to be sentenced to prison because he was "psychotic" during the July 22 attacks that led to the deaths of 77 people and injured 151. The 243-page evaluation still has to be reviewed by a panel from the Norwegian Board of Forensic Medicine.

Canada and Norway have different criteria for finding a person mentally unfit, and who makes that determination also differs between the two countries.

"Each country has different criteria that they impose on how you determine whether a person is criminally responsible for their behaviour. And in Canadian jurisprudence, as well as all Commonwealth countries and the U.S., that decision is only made by the courts, not by psychiatrists," O'Shaughnessy said.

Under Section 16 of Canada's Criminal Code, a person is deemed to be not criminally responsible (the term 'insane' having been scrapped) if the crime was committed while "suffering from a mental disorder that rendered the person incapable of appreciating the nature and quality of the act or omission or of knowing that it was wrong."

O'Shaughnessy said the issue of responsibility is determined by a number of factors.

"Did the person have a severe mental disorder at the time of the offence. They're clearly saying [Breivik] did. But in Canadian jurisprudence, simply having a mental disorder, even severe, doesn't mean you're going to be held not criminally responsible.

"You then have to apply the disorder to the facts of the case and reach the conclusion as to whether the disorder was of such severity that it caused him to be unaware what he was doing was wrong in a moral as well as legal sense."

O'Shaughnessy said an accused person can be delusional and have beliefs that are incorrect but may still be held responsible if that person appreciates what they were doing was wrong.

"You may well believe there are elements of society that are evil or they've harmed you in some way and you want to get revenge on them. You would still be well aware that that behaviour is wrong."

O'Shaughnessy said it's difficult to conclude whether Breivik would be considered not criminally responsible in Canada without knowing details about his mental state.

"Quite literally, the devil is in the details," he said.

Osgoode Hall Law School Prof. Alan Young said the person has to suffer from some kind of cognitive impairment — someone who can't perceive reality or appreciate the nature and quality of their act, has some kind of psychosis or break with reality due to delusions.

According to Norwegian prosecutors, the psychiatric report described Breivik as a man "in his own delusional universe" where all his thoughts and acts are governed by these delusions and that during a long period of time developed the mental disorder of paranoid schizophrenia, which changed him.

"Here's the bottom line for Canadian law. Delusions or no delusions," Young said. "The only relevance of a delusion would be if it affects his capacity to appreciate the nature and quality of the act. Which means, did he understand he was firing a gun which had the potential to kill somebody? And clearly he did.

"Or he could be found insane if his delusions led him to believe that his actions were morally justifiable. That I don't know but I would doubt that because it just seems that he was getting his inspiration from his own ideological thought patterns and not acting on behalf of some greater power.

"So my preliminary assessment on limited facts, would be … [Breivik] would be found sane by Canadian and American standards."

But Young said further information could reveal that Breivik believed his delusional set of beliefs were sanctioned from a higher power, meaning he might be considered not criminally responsible.

Patrice Band, a Toronto criminal defence lawyer, added that some who believe they must declare war on the powers that be because they have a certain ideological persuasion may not be delusional or psychotic.

"It just may be a political mindset. And I'm not sure which it is in the case of Breivik because the stuff you read about his manifesto really sounded like the latter, he really believed he was engaged in social and policy warfare.

"Whether he actually believed as a matter of fact he was acting in self-defence is another story."