Typical Film Noir Structure

Crime, usually murder, is an element of almost all film noirs; in addition to standard-issue greed, jealousy is frequently the criminal motivation. A crime investigation—by a private eye, a police detective (sometimes acting alone), or a concerned amateur—is the most prevalent, but far from dominant, basic plot. In other common plots the protagonists are implicated in heists or con games, or in murderous conspiracies often involving adulterous affairs. False suspicions and accusations of crime are frequent plot elements, as are betrayals and double-crosses.