'JOKER' PICKS WRONG PERSON TO JACK: A Pittsburgh man who tried to car-jack a car driven by a plain-clothes police officer tried to cover his butt by blaming Batman! Yes, the Caped Crusader.

Detective DiGiacomo was tooling around in an unmarked police car looking for a suspect in an assault when 21-year-old Micah Calamosca opened the car door, sat down and told DiGiacomo to get out.

When the undercover cop drew his weapon and indentified himself, Calamosca insisted he was part of the team in town to film the new Batman movie The Dark Knight Rises -- and that the car-jacking was part of the script.

The boys in blue didn't buy it and now Calamosca faces charges of robbery of a motor vehicle.