Police near Baltimore say they may have stopped a mass shooting modeled on the Dark Knight tragedy, reports the Baltimore Sun. Authorities arrested a 28-year-old man in Crofton who phoned his former employer, threatened to "shoot the place up," and referred to himself as the "joker," reports AP. Police found nearly two dozen guns in his home, including assault rifles. Neil Prescott is being held at a medical facility in Annapolis, where he is undergoing a psychological exam. He had apparently just lost his job at Pitney Bowes.