The Killer Must Kill Again (L'assassino è costretto ad uccidere ancora), also known as The Dark is Death's Friend, is a 1975 Italian giallo film directed by Luigi Cozzi.
Synopsis
Giorgio is a greedy adulterer who makes a deal with a serial killer to dispose of his wealthy wife, Nora. Unfortunately, a thrill-seeking young couple steal the killer's car with Nora's corpse in the trunk, ending up at a run-down seaside villa. The killer follows their trail and eventually finds them, violently raping the young girl when he finds her alone, then he kills her boyfriend upon his return. Now the young girl is left to fend for herself against the merciless killer.