A Quebec Superior Court judge has ruled that a Montreal man who killed his parents and grandmother is not criminally responsible, concluding that severe mental illness rendered him incapable of understanding the nature or moral consequences of his actions.
Arthur Galarneau, 22, showed little reaction in court as Annie Émond delivered her decision Thursday, accepting a joint submission from the Crown and defence following a two-day trial held in December. Psychiatric experts testified that Galarneau was suffering from schizophrenia marked by delusions, hallucinations and acute psychosis at the time of the killings.
In her ruling, Émond said Galarneau’s mental state was so profoundly disturbed that he lacked the capacity to rationally judge whether his actions were morally wrong or to fully comprehend their nature. As a result, she said, he could not be held criminally responsible for the deaths.
Galarneau had been charged with second-degree murder in connection with the March 17, 2023 deaths of his mother, Mylène Gingras, 53, his father, Richard Galarneau, 53, and his grandmother, Francine Gingras-Boucher, 75, at the family home in Montreal.
The court heard that on the morning of the killings, Galarneau’s mother placed a frantic call to 911 from an apartment in the Rosemont–La Petite-Patrie neighbourhood, pleading for help before the call abruptly ended. Police traced the call to a duplex on Bélanger Street, an address previously known to authorities for mental health-related incidents.
When officers arrived, they forced entry into the residence and arrested Galarneau, who was taken into custody after resisting police and exhibiting clear signs of psychological distress. During the arrest, he spoke about demons and the devil and repeatedly asked officers to kill him.
Evidence presented in court detailed a history of serious mental illness. Galarneau’s schizophrenia symptoms first emerged in 2020, when he was a teenager, and fluctuated depending on whether he was taking prescribed medication. His parents, who had separated years earlier but remained on good terms, had recently reunited in the same household in an effort to care for him as his condition worsened. The court heard they had attempted to secure urgent psychiatric help and had moved up a medical appointment shortly before the killings.
In the days leading up to the attacks, Galarneau believed his parents were conspiring to have him hospitalized, a fear that psychiatrists said was rooted in his psychosis. The judge noted that these delusions played a significant role in the events that unfolded.
While Galarneau continues to suffer from mental illness and requires ongoing treatment, Émond told the court he has since demonstrated some insight into his condition. During a 2025 assessment with Crown-appointed psychiatrist Gilles Chamberland, Galarneau criticized the mental health system, saying earlier intervention might have prevented the deaths. According to the report cited by the judge, he acknowledged that his parents did everything they could to help him but did not know where else to turn.
The Crown has indicated it will seek a high-risk offender designation, which would result in Galarneau being detained in a secure psychiatric facility, subject to longer intervals between reviews and oversight by the Superior Court. Émond ordered a further psychiatric evaluation to assess that request, with the case scheduled to return to court on Feb. 23. Defence lawyers have said they will oppose the designatio