A detective is an investigator, usually a member of a law enforcement agency. Some are private persons, and may be known as private investigators, as "The Eye That Never Sleeps", the motto of the Pinkerton Detective Agency or shortened to simply "private eyes". Informally, and primarily in fiction, a detective is any licensed or unlicensed person who solves crimes, including historical crimes, by examining and evaluating clues and personal records in order to uncover the identity and/or whereabouts of the criminal.