A detective is an investigator, either a member of a police agency or a private person. The latter may be known as private investigators (P.I.s or "Private Is", hence the play-on-words, "Private Eyes"). Informally, and primarily in fiction, a detective is any licensed or unlicensed person who solves crimes, including historical crimes, or looks into records.
Captain Jim Brass is a notable and very successful homicide detective.
Sofia Curtis was a Las Vegas Detective, Stella Bonasera was a New York Detective, and Frank Tripp is Homicide Detective in Miami.