Crime films focus on the lives of criminals and their evil deeds, ranging from realistic portrayals to exaggerated villains overcome by heroes. Common conventions include morally upright protagonists investigating crimes like murder in dangerous areas. The protagonist often has a personal stake and the plans become more intricate over the film, with the hero prevailing and romantically rewarded or avenged. Subgenres are crime comedies mixing humor, crime thrillers emphasizing action/drama, film noir of the 1940s-60s, and heist films of robbery plots. Other genres depict gang problems or Mafia activities.