First part of police commissioner Betti's trilogy, also including Violent Naples (1976) and A Special Cop in Action (1976).
John Steiner worked for four days on this film. He said that after the movie came out, everybody in Italy knew who he was and was recognised everywhere he went. He said it did more for his career than anything else.
Richard Conte's voice was dubbed by another actor in the English language version.
Italian censorship visa # 66956 delivered on 4 August 1975.