The
police procedural, or
police crime drama, is a subgenre of
detective fiction which attempts to convincingly depict the activities of a
police force as they investigate
crimes. While traditional detective novels usually concentrate on a single crime, police
procedurals frequently depict investigations into several unrelated crimes in a single story. While traditional mysteries usually adhere to the convention of having the criminal's identity concealed until the
climax (the so-called
whodunit), in police procedurals, the perpetrator's identity is often known to the audience from the outset (the
inverted detective story). Police procedurals depict a number of police-related topics such as
forensics,
autopsies, the gathering of
evidence, the use of
search warrants, and
interrogation.