When a prostitute is murdered in a motel room, and an eyewitness points his finger at a cop, it seems an open and shut case - especially when the officer can't explain the fact that his gun, which never left his holster, is the murder weapon. But Officer Ben Grasso, new to the police force but not to the street, isn't buying the official story. As he begins his unauthorized investigation, Grasso is assigned a new partner - Dina Greenbaum. She quickly learns of her partner's dangerous investigation and, despite lessons from her past that should have warned her away, she decides to help....