However, legal scholars say it's unlikely the 24-year-old will face the maximum penalty — 75 years in prison before he is eligible to apply for parole — given his age and lack of a criminal record.
In early August, Bourque pleaded guilty to three charges of first-degree murder and two counts of attempted murder.
A single conviction for first-degree murder carries a mandatory life sentence and a ban on applying for parole for 25 years. However, Judge David Smith of the Court of Queen's Bench has said the Crown wants him to use a 2011 amendment to the Criminal Code that allows judges to extend parole ineligibility in the case of multiple murders.
In this case, Smith could decide that the 25-year ineligibility period for each murder conviction should be imposed consecutively, which means Bourque wouldn't be allowed to apply for parole until he was 99 years old.
The Harper government changed the law to eliminate what it called the "volume discount" for multiple murderers.
The law has been used only once since it was changed. In September 2013, a judge in Edmonton sentenced an armoured-car guard to life in prison with no chance at parole for 40 years for gunning down four of his colleagues during a robbery in June 2012.
Travis Baumgartner had pleaded guilty to one count of first-degree murder, two counts of second-degree murder and a charge of attempted murder.
It was the toughest criminal penalty since Canada's last executions in 1962.
Baumgartner was facing a 75-year parole ineligibility period, but the judge cited mitigating factors, including his age, lack of a criminal record and his guilty pleas, which prevented a prolonged trial.
It's for these same reasons that law professor Isabel Grant believes Bourque will be given a lighter sentence.
"I would be surprised if the court imposed 75 years on someone his age," said Grant, who teaches at the University of British Columbia. "To make the jump to 75 years would be quite dramatic."
As well, Grant said the judge may consider mental illness as a mitigating factor during the two-day hearing.
Though Bourque was recently found competent to stand trial after undergoing a psychiatric assessment, an affidavit filed by his father Victor says that in the 18 months before the shootings, Justin Bourque's mental or emotional state deteriorated to the point he was "ranting and raging against all authority."
The affidavit says the young man went from living peacefully with his parents and six siblings in Moncton to buying guns, getting kicked out of the house and becoming depressed and paranoid.
Allan Manson, a law professor at Queen's University in Kingston, Ont., said the judge has to be careful not to impose a sentence that could be the subject of a constitutional challenge on the grounds it amounts to cruel and unusual punishment.
"There is ample evidence of serious psychological effects that stem from long-term incarceration," Manson said in an interview.
Archie Kaiser, a law professor at Dalhousie University in Halifax, said the Criminal Code states that when consecutive sentences are imposed, they should not be "unduly long or harsh."
"A person ... sentenced to serving his or her whole life in penitentiary could effectively lose hope," he said.
"Saying that somebody has to be in prison for that long also diminishes one's confidence in the ability of the prison system to rehabilitate inmates. ... It does begin to look more like vengeance and less like a fit and appropriate sentence."
An agreed statement of facts filed with the court says Bourque's "actions were both planned and deliberate" when he used a Poly Technologies M305, 308-calibre semi-automatic rifle to kill constables Dave Ross, Fabrice Gevaudan and Douglas Larche.
The officers were responding to a report of a man carrying firearms in a residential neighbourhood in the northwest area of Moncton on June 4.
Constables Eric Dubois and Darlene Goguen were wounded and later released from hospital.
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