Idelson Guerrier, 31, was arrested after allegedly attacking a fellow patient in the psychiatric ward. Police are currently investigating any links between the suspect and two deaths in the same ward that happened between June 16 and June 22.
Guerrier was admitted to Notre-Dame on June 16. The same day, a 69-year-old man was found dead.
Kevin Boire, spokesperson for Action-Autonomie, a group that offers legal aid to people with mental illnesses, said he hears of similar attacks "all too often."
"We receive a lot of complaints from people who say they're left alone, unsupervised," Boire said.
Action-Autonomie's executive director, Ella Amir, said she has noticed significant cuts to the mental health services in the province. These results in fewer beds and fewer services accessible to patients in need.
The hospital said it is reviewing Guerrier's file and carrying its own investigation on the three attacks. But well known medical lawyer Jean-Pierre Ménard said a review isn't enough. He is calling for a full coroner's inquiry so such attacks can be prevented.
Guerrier is undergoing a court-ordered psychological evaluation.