Crime fiction, detective story, murder mystery, mystery novel, and police novel are terms used to describe narratives that centre on criminal acts and especially on the investigation, either by an amateur or a professional detective, of a crime, often a murder. It is usually distinguished from mainstream fiction and other genres such as historical fiction or science fiction, but the boundaries are indistinct. Crime fiction has several subgenres, including detective fiction, courtroom drama, hard-boiled fiction, and legal thrillers. Most crime drama focuses on crime investigation and does not feature the courtroom. Suspense and mystery are key elements that are nearly ubiquitous to the genre.

Hardboiled fiction is a literary genre that shares some of its characters and settings with crime fiction. The genre's typical protagonist is a detective who battles the violence of organized crime that flourished during Prohibition (1920–1933) and its aftermath, while dealing with a legal system that has become as corrupt as the organized crime itself. Rendered cynical by this cycle of violence, the detectives of hardboiled fiction are often antiheroes. Notable hardboiled detectives include Dick Tracy, Philip Marlowe, Nick Charles, Mike Hammer, Sam Spade, Lew Archer, Slam Bradley, and The Continental Op.