James McLevy was an Irishman who moved to Edinburgh, Scotland where he worked as a builder's labourer and then became a policeman in 1830. In 1833 he became a detective, rising to the rank of Police Detective Inspector in the Parish of Leith, Edinburgh. This real life policeman handled over 2200 cases during his 30 year career and it was said that he always secured a conviction.

James McLevy was born in Ballymacnab in County Armagh, Ireland. His father was a farmer. He was notorious for not liking the English.