A 26-year-old man has been ordered to undergo a mental health assessment after prosecutors allege he fatally stabbed his stepfather and seriously wounded three other people in downtown Montreal last weekend.

At the request of his lawyer, Guillaume Dion Roy will undergo the assessment at the Philippe Pinel Institute to determine if he is mentally fit to stand trial on charges of second-degree murder and three counts of attempted murder, the Crown prosecutor confirmed to CTV News.

Montreal police were called at 6:50 a.m. Sunday to an apartment on Drummond Street, near Sherbrooke Street, after, they allege, the young man stabbed his 72-year-old stepfather, his mother and two other people.

The man's stepfather has been identified as Montreal lawyer Raymond Hébert. He suffered serious stab wounds and was pronounced dead at the scene.

Hébert worked at the De Grandpré Jolicoeur law firm, about four blocks from the scene of the crime, where he specialized in commercial leases, according to a bio on the firm’s website. He was also a member of the Canadian Ski Coach Federation.

His colleagues say they are mourning his tragic death.

"Our colleague Raymond was a generous, dedicated, and approachable man," wrote Isabelle Poirier, a senior partner with the firm, in a statement to CTV.

"He was a passionate and rigorous lawyer, a team colleague, who was always committed to advising and representing his clients in a professional manner," she said.

"His passing leaves us in deep sadness."

The killing was the city's 13th homicide of the year.

The accused is scheduled to return to court on July 5, when the court is expected to review a report based on the mental health assessment.