http://www.cbc.ca/news/canada/sudbur...sons-1.3653957

On June 12, 1966, 27-year-old Philippe Guérin went missing from the Ontario Hospital, a psychiatric hospital located in the north end of North Bay and that has since been demolished...

​At the time he was reported missing, Guérin was described as 5'-7" tall, with a medium build, short brown hair, brown eyes, and he had no upper teeth. When he was 10, Guérin was paralyzed by polio, and walked with a limp.
http://www.nugget.ca/2016/06/27/fami...after-50-years

On Monday morning, the North Bay police service held a press conference asking anyone with information that could help locate Guerin to contact them. The 50-year-old case is the oldest unsolved missing persons file in the history of the North Bay Police Service.

Ontario Hospital was unaware of Guerin's disappearance for at least a month after it happened. He had been admitted to the hospital because he had become aggressive towards his parents...

The Widdifield Police followed a lead from a North Bay clergyman who picked up a hitchhiker matching Philippe's description in the Sudbury area, but this did not lead them anywhere.