Based on the real-life Richard Speck murders, amoral, nearly psychotic killer Warren Stacey (Gene Davis) is a serial killer who has murdered a number of women; he stabs them while they are naked to minimize leaving any physical evidence. Police detective Leo Kessler (Charles Bronson) is convinced of Stacey’s guilt and, over the objections of his partner, plants evidence to get him behind bars. When Stacey is released on a technicality, he threatens to go after Kessler and his family, leaving Kessler to defend himself against a killer with little help from the police.