They said Radoslaw Szalankiewich left a hospital in Montreal’s Rosemont neighbourhood before his evaluation was finished Monday afternoon.
It’s believed he’s either in Montreal or Ottawa.
He is described as a white man around six feet one inch tall and weighing around 145 pounds with blonde hair and hazel eyes.
Montreal police are warning anyone who sees Szalankiewich to not approach him, because he could become aggressive.
Police said given the man's past history, he could also be suicidal.
Anyone who sees him is asked to call 911.