Term used until approximately the mid-
20th century for a private
detective kept on staff by a
hotel or a reasonably large
store. More skilled than a
security guard, closer resembling a modern day
chief of security. Also a close relation of
floorwalker.
House detectives were responsible for preventing or stopping theft, vandalism and various forms of troublemaking in the hotel, as well as subduing violent guests or visitors and getting rid of nuisances (i.e., prostitutes).
The term frequently appears in 1920s to 1960s crime fiction, often replaced by one of its synonyms. A house detective is also known as house dick, house cop, house copper, house peeper, or a combination of hotel or store with any of the above (hotel detective, etc).