For more than 30 years, retired Ontario Provincial Police Sergeant Barry Ruhl has believed that a criminal with whom he had a violent encounter early in his career might be responsible for a string of unsolved murders of young women in Ontario, including the 1959 death of 12-year-old Lynne Harper. The only suspect ever investigated in that sensational case was 14-year-old Steven Truscott, who was convicted and sentenced to hang before being cleared...