A step-by-step look at a murder investigation on the streets of New York.

In the late hours of a hot New York summer night, jewel thieves Willie Garzah and Peter Backalis kill Jean Dexter, an ex-model, then place her body in her bathtub. When Backalis gets drunk after the murder, Garzah kills him, then dumps his body in the East River. Later, Homicide detective Dan Muldoon and his young associate, Jimmy Halloran, are assigned to Jean's case, which the medical examination has determined was murder, not an accident. While Dan interrogates Martha Swenson, Jean's housekeeper, about Jean's boyfriends, Jimmy questions Dr. Lawrence Stoneman, Jean's physician, and Ruth Morrison, another model. Back at the police station, Dan questions Frank Niles, Jean's ex-boyfriend, who lies about everything, including his current engagement to Ruth. Later, Dan determines from the bruises on Jean's neck that she was killed by two men. That evening, Mr. and Mrs. Batory, Jean's estranged parents, arrive in New York to formally identify the body, and tell the detectives that they have no knowledge of Jean's acquaintances. The next morning, the detectives learn that Frank sold a gold cigarette case stolen from Stoneman, then purchased a one-way airline ticket to Mexico. They also discover that Jean's ring was stolen from the wealthy Mrs. Hylton, Ruth's mother. Learning that Ruth's engagement ring is also stolen property, Dan and Jimmy rush to Frank's apartment, where they save him from being murdered by Garzah. The killer escapes onto the nearby subway train, however, and when questioned about the stolen jewelry, Frank claims that they were all presents from Jean. Frank is then arrested for robbery, but the murder case remains open. When Backalis' body is found, Jimmy attempts to connect the ex-convict to Jean's murder. Through further investigation, Jimmy discovers that Backalis' accomplice on a jewelry story robbery was Garzah. While Jimmy canvases the Bronx with an old wrestling photograph of Garzah, Dan forces Frank to admit that Stoneman was Jean's mystery boyfriend and goes by the name Henderson. Back at Stoneman's office, the married physician confesses that he fell in love with Jean, only to learn that she and Frank were using him in order to rob his society friends. Frank then admits that Garzah killed Jean and Backalis. Meanwhile, Jimmy attempts to arrest Garzah by himself, but is knocked unconscious by the homicidal wrestler. A panicked Garzah then draws attention to himself when he shoots and kills a blind man's guide dog. Trapped atop a bridge, Garzah refuses to surrender to the police and is shot, then falls to his death.