Homicide Detective Lt. Dan Muldoon and his young associate, Det. Jimmy Halloran, are assigned to Jean's case, which the medical examination has determined was murder. Muldoon has been a homicide cop for 22 years, Halloran for three months. At the scene, the police interrogate Martha Swenson, Jean's housekeeper, about Jean's boyfriends, and she tells them about a "Mr. Henderson". They also discover a bottle of sleeping pills and her address book. Halloran questions the doctor who prescribed the pills, Lawrence Stoneman, and Ruth Morrison, another model and Jean's friend. Back at the police station, Muldoon questions Frank Niles, Jean's ex-boyfriend, who lies about everything, claiming only a business relationship with Jean and denying knowing Ruth. Because of his lies, Niles becomes the prime suspect. Later, Muldoon deduces from the bruises on Jean's neck that she was killed by at least two men.