If Joker DOES beat someone to death with a crowbar the scene should be told by one of his henchmen that was caught at the scene. While being interrogated by police, and looking quite disturbed at what has transpired, the henchman explains to the police how Joker just seemed to "snap". The scene should be done with alternating shots between the interrogation room and flashbacks of the events. The Henchman's explaination of the events should be dubbed over the quick flashbacks to add a nice flow to the scene. (I hope you guys can understand this) When we get to the actual beating the shot can be either of the Henchmen's horrified face at the scene or the look on the policemen's face while he tells it.. finishing with a flashback of the joker's hand holding a crowbar in focus while the bloody body is at a distance out of focus..all the while hearing his horrific laugh. That would be the point where the joker goes from a brutal crime thief to a lunatic murder.