Dragnet (1967)

S04E07 Homicide - Cigarette Butt

Joe and Bill delve into a murder case after discovering a corpse in a dilapidated apartment complex. Among the evidence, they find a knife and a half-eaten peanut butter sandwich at the crime scene. A nearby resident reports seeing a man and woman fleeing the apartment. The couple soon returns, claiming they acted in self-defense. Determined to uncover the truth, Joe begins to search for clues that could either confirm or refute their story.