Maniac Cop is an '80s B-movie with a fairly simple premise. The streets of New York are being terrorized by a killer in a police uniform, and the NYPD must figure out who it is while the city grows ever more distrustful of them. The movie features Bruce Campbell between his roles in Evil Dead II and Army Of Darkness, though the true lead of the film is an older detective played by Tom Atkins.
The film plays very much like a police procedural. In between the scenes of killing we get Detective Lieutenant Frank McCrae tracking down leads to piece together who the killer is. He's convinced that it must be an officer within the NYPD, though the commissioner is eager to downplay these theories which just makes McCrae's search tougher.
The movie is a pretty fun slasher. While it isn't mind-blowing in any way, I think it accomplished exactly what it set out to do. I feel like it could have used some more visually exciting death scenes and sometimes it dragged a little, but it does a good job of showing the panic that ensues when the police can't be trusted.