Green’s Dictionary of Slang

a detective, a police officer, a melodramatic image, esp. popular in the tabloid press.

1936		Michigan State Police Annual Report 86: FIRST VETERAN OFFICER TO RETIRE CAPTAIN IRA H. MARMON, an ace crime-buster through a quarter of a century of Michigan State Police history [etc.].
1938		Christian Century 55 1164/1: George E. Q. Johnson, former United States district attorney, himself a notable crime-buster.
1952		Manchester Guardian Wkly 31 July 7/1: The tall prim crime-buster came forward to a heartrending ovation from his supporters.
1962		K. Orvis Damned and Destroyed 9: A man who takes pleasure in being called crime-buster – promises without delay to put vice on ice in Montreal.
1999		Guardian Guide 5–12 June 89: This has [...] fast Porsches, big hair, small bikinis, and scantily-clad crimebusters of both sexes.