Now that this survey of crime subgenres has ended, it is time to return to the question that haunted its opening chapter: What is illuminated by considering a given film like The Godfather (1972) or Murder on the Orient Express (1974) or Fargo (1996) as a crime film rather than a gangster film or a detective story or a black comedy? More generally, what is gained by defining the crime film as a strong genre that not only incorporates but logically underpins such better-known genres as the gangster film, the private-eye film, the film noir, and the police film? Discussing crime comedies like Fargo as crime films that happen to be humorous rather than comedies that happen to involve crime seeks to expand the range and resonance of the crime genre at the risk of choosing examples many viewers might dismiss — and indeed of diluting the genre as a whole. Many viewers, perhaps most, do experience The Thin Man (1934) or Charade (1963) or Fargo as crime films with comic relief, but how many viewers, after all, would categorize Arsenic and Old Lace (1944) or The Trouble with Harry (1955) or Some Like It Hot (1959) as crime films rather than comedies?

The point of discussing such films as crime films is not to inflate the importance of one genre at the expense of another but to indicate the ways in which previous definitions of crime films may have been unwisely parochial.