Inverted detective story

The inverted detective story is a crime-fiction structure in which the commission of the crime is shown or described at the beginning, usually including the identity of the perpetrator, after which the story follows the detective's attempt to solve it. It is the structural opposite of the whodunit: the reader knows who did it from the opening pages, and the suspense moves from who to how the culprit will be caught. The colloquial name is the howcatchem, coined by Philip MacDonald in 1963 and popularized in the 1970s mostly through the television series Columbo, which remains perhaps the best-known example of the form.

R. Austin Freeman invented the format with "The Case of Oskar Brodski" (1912), on the observation that a reader who has watched the crime is "so occupied with the crime that he would overlook the evidence", so the investigation reads as new material rather than repetition. Early novels include Anthony Berkeley Cox's Malice Aforethought (1931) and Freeman Wills Crofts's The 12.30 from Croydon (1934), and the line runs through Dial M for Murder to television procedurals and manga such as Death Note.

Because the reader always knows more than the cast does, the inverted story runs on dramatic irony rather than puzzle-solving: the writer's game is the slow closing of the net, which makes it a natural sibling of the police procedural rather than the fair-play mystery's deduction game, though subsidiary puzzles, such as motive, can still be held back from the reader.