Police State (1987)

Zedd is minding his business, when he is stopped by a cop who accuses him of being a junkie. After a short argument he is beaten and dragged to the police station. At the station he is interrogated by a detective (Rockets Redglare) and the police chief. After being beaten and tortured several more times, Nick Zedd's character mutilates himself with some hedge cutters.

Unfortunately the movie Police State is not yet available on HBO Max.