The Stepfather is a 1987 American
horror thriller film directed by
Joseph Ruben, and starring
Terry O'Quinn,
Jill Schoelen, and
Shelley Hack. O'Quinn stars as Henry Morrison, a identity-assuming serial killer who remarries a widow with her teenage daughter. After previously killing his family and changing his identity, his killing spree continues after his daughter turns suspicious about him. It is loosely based on the life of mass murderer
John List, although the plot is more commonly associated with
slasher films of the era than a true story. The film was written by
Donald E. Westlake, from a story by Westlake, Carolyn Lefcourt and
Brian Garfield.