Police procedural
The police procedural, police show, or police crime drama is a subgenre of procedural drama and detective fiction that emphasises accurate depiction of the investigative procedure of police officers, police detectives, or law enforcement agencies as the protagonists, as contrasted with other genres that focus on non-police investigators such as private investigators (PIs). Many mysteries that feature a policeman as the protagonist—for example, Earl Derr Biggers's novels featuring Honolulu Police detective Charlie Chan, Ngaio Marsh's novels and short stories about Roderick Alleyn of Scotland Yard, and the TV series Columbo—are not meant as authentic depictions of the law enforcement profession, but are merely giving the protagonists an official position so that they have a "franchise," so to speak, from which to work.