This is the companion film to Detenute violente (1984). Because both films are directed by Gianni Siragusa (as Willy Regan) and feature most of the same cast, they are often confused with each other and believed to be one film. However, they are two entirely different films.
Incorrectly attributed to Sergio Garrone by some sources, this movie was actually directed by Gianni Siragusa (as Willy Regan).