**_Joe Spinell as a fudged-up murderer in New York City_** “Psycho” started a subgenre of films about mentally messed up people who go on killing sprees. For instance, the ’70s brought us movies like “Haunts,” “The Toolbox Murders,” “The Driller Killer” and “Don’t Go in the House.” “Maniac” comes in the tradition of these flicks while adding bits from the Dirty Harry franchise, “Dawn of the Dead” and “The Warriors.” It’s gritty in its depiction of the sometimes repugnant underbelly of the city, but IMHO focuses too much on the killer stalking his victims, particularly, the nurse in the s...