Maniac Cop [1988, USA, horror, DVD5]

In New York, a tall and strong man dressed like a NYPD officer is killing innocent people in the night. Detective Frank McCrae is assigned to investigate the case and suspects that either a police officer or a whistleblower is providing inside information to the killer. McCrae discloses the information to a journalist, and the killer is called the maniac cop by the press. When the police officer Jack Forrest is accused of killing his wife Ellen Forrest in a cheap motel room, he is arrested. But he holds the name of his lover that could give an alibi to him, the cop Theresa Mallory, to protect her. McCrae is convinced that Forrest is innocent and was framed, and asks Forrest and Theresa who knew their love affair. Theresa tells that she disclosed her secret to the crippled Sally Noland, who works in bureaucratic department. McCrae follows this lead and reaches the name of a cop that died in Sing Sing, Matt Cordell. Now he intend to investigate what happened to Cordell in the prison.