Age: 17
Sex: female
Date: 19 Mar 1976
Place: Third Avenue, Bonhill, West Dunbartonshire
Mary Duncan vanished from her home in Bonhill on 19 March 1976.
When she left her home she said that she was going to meet a friend.
In August 2020 the police said that they were conducting searches at the Vale of Leven Hospital for her. In September 2020 the police said that they were extending their search to a residential site in Helensburgh.
