LAVAL — The Quebec man who killed two children and injured six others when he drove a city bus into a Montreal-area daycare in 2023 committed an act so brutal that he must be considered a high-risk offender, a Crown prosecutor argued on Friday in Superior Court.
And while Pierre Ny St-Amand was declared not criminally responsible for his actions because of a mental disorder, there is a “significant likelihood” that he will be violent again, prosecutor Simon Blais told the judge.
“It is difficult to imagine an act more cruel, savage, or inhumane than that committed by the accused in this case,” Blais told the courtroom in Laval, Que., the Montreal suburb where on Feb. 8, 2023, Ny St-Amand drove a bus into a daycare, killing a four-year-old boy and five-year-old girl and injuring six other children.
“You have an act of extreme violence, and you have actions that involve young children without defence in a daycare, therefore in a place where we are supposed to be assured of their safety,” Blais said.
The Crown is seeking to have Justice Éric Downs declare Ny St-Amand, 53, a high-risk offender, a designation that would impose stricter rules on him while he is detained at a psychiatric hospital, and limit the decisions that the province’s mental health review board can make in his case. Any changes to his treatment plan or on the restrictions of his movements would need to be put to the Quebec Superior Court.
Blais said that having both the mental health board and the Superior Court sign off on his movements is a “two-step validation process … necessary to ensure that an appropriate decision is made.”
Ny St-Amand’s lawyers, meanwhile, are opposing the Crown’s application, and they have challenged the constitutionality of the high-risk designation. On Friday, Véronique Talbot told the court the designation is “discriminatory” and that it can affect Ny St-Amand’s ability to access treatment for his mental health problems.
“In the context of everything we’ve heard … it’s contrary to the legislator’s intention that Mr. Saint-Amand be in this high-risk category,” Talbot told the court.
“From a medical point of view as well … there won’t be any benefits … it’s even going to be contrary, because it will be an additional source of stress … and we’re removing the tools (to help him).”
She also noted the province’s mental health board, which oversees cases in which people are found not criminally responsible, is rigorous and doesn’t need the Superior Court to affirm its decisions.
In April, Downs ruled that Ny St-Amand was likely in psychosis when he crashed the bus into the daycare, killing Jacob Gauthier and a girl named Maëva, whose family name is covered by a publication ban at the request of her parents.
Ny St-Amand was born in Cambodia in 1972, shortly before the Khmer Rouge began a brutal rule that is blamed for the deaths of 1.7 million people. Both his parents died in the conflict, and he doesn’t know his real surname or birthday. He was moved to different refugee camps under the guardianship of a cousin, who also died. He was physically assaulted by the cousin’s wife, who strung him up by his feet and beat him. In 1982, he was sent to Canada by a humanitarian agency and adopted by a Quebec family.
During this trial, psychiatrists who evaluated him said his past and lack of close personal relationships left him poorly equipped to cope with stressors.
Three experts — two psychiatrists for the Crown and a psychologist hired by the defence — testified during the hearing this week. Dr. Sylvain Faucher, a forensic psychiatrist, described St-Amand’s risk to reoffend as “at least moderate.” Dr. Alexandre Hudon, another psychiatrist, pegged the probability of Ny St-Amand having another psychosis episode at better than 50 per cent.
Hudon said Ny-St-Amand meets the requirement for the designation, but added it would do little to help with risk management in his case. Already at Montreal’s Philippe Pinel Institute, he’s in detention without outside access.
Blais said the reason the former city bus driver crashed into the daycare remains unexplained. Ny St-Amand maintains he doesn’t remember what happened. The prosecutor said the Crown is not saying that Ny St-Amand doesn’t have the ability to respond to treatment or hasn’t shown improvement since his 2023 arrest.
“But based on the progress he’s made since his arrest in 2023, our contention is that currently he has a significant likelihood of violent recidivism,” Blais said.
Downs’s decision on Ny St-Amand’s status will have to wait until the constitutional challenge is settled. The judge is scheduled to hear arguments on the challenge during the week of Nov. 10.
This report by The Canadian Press was first published Sept. 19, 2025.
Sidhartha Banerjee, The Canadian Press
