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.