The man who pleaded guilty to pulling the trigger and killing three people, then seriously injuring a fourth, appeared in court Monday at the start of his week-long trial – which could end in a precedent-setting sentence.

The Crown put forward a joint submission for sentencing Monday, to sentence Travis Baumgartner to serve 40 years behind bars before being eligible for parole – submission the Crown said Baumgartner’s defence agreed with.

If Justice John Rooke agrees to that sentence, it would become the harshest sentence handed down in a Canadian courtroom since the last time a convicted criminal was sentenced to death in Canada. The last execution was performed in Ontario in 1962.

If the sentence is handed down, Baumgartner would not be eligible for parole until 2052.

The lengthy sentence comes as a result of changes to the Criminal Code of Canada, previously, sentences could not continue longer than 25 years, before a convicted criminal could be eligible for parole.

Baumgartner was charged with first-degree murder in the deaths of three of his co-workers, and attempted murder in the serious wounding of a fourth co-worker.

He’s accused in the bloody armoured car heist that unfolded at HUB Mall on the University of Alberta campus in June 2012.

Baumgartner, a former G4S guard, was part of a team of five guards who were reloading ATM machines on the campus – when the shots rang out.

In the end, three guards, Brian Ilesic, 35, Eddie Rejano, 39, and Michelle Shegelski, 26, were dead – Matthew Schuman, who was 25 at the time, survived the shooting with a bullet to the head.

In court, Baumgartner pleaded guilty to two counts of second degree murder, one count of first degree murder and one count of attempted murder.

The charges of second degree murder stemmed from the shooting deaths of Ilesic and Shegelski, and the first degree murder charge is for Rejano’s death.

After his pleas were entered, court began hearing emotional victim impact statements from family of the three guards slain in the shooting.

Not long after the bloody scene unfolded, police quickly named Baumgartner, who was 21 at the time, as a suspect, and launched a massive search for him.

He was arrested the next day in B.C., at the Canada-U.S. border; he had a backpack with him containing $334,000.

Evidence gathered in search warrants revealed Baumgartner’s mother told police she woke up the morning of the shooting to find $64,000 in cash in her house.

Court documents also revealed Baumgartner had argued over rent money he had failed to pay her.

The trial is being heard by a judge, without a jury.

Justice Rooke will release his decision on Baumgartner’s sentencing Wednesday at 10 a.m.

With files from Serena Mah, David Ewasuk and The Canadian Press