Trivia: The font used for Live With Murray Franklin is identical to the Batman animated series titles. The name of the font is "Plaza," for those that might be curious.
Trivia: Arthur has a copy of The Blue Boy by Thomas Gainsborough hanging on his wall. The same painting is appreciated by Joker in the 1989 Batman movie.
Continuity mistake: At the end when Arthur/Joker dances on the police car's hood in front of the crowd, in the shot behind him he keeps his arms down, but when it changes into a frontal shot on him he keeps them lifted up.
Continuity mistake: When Joker confesses that he was the one who killed the three guys in the subway at the Murray Franklin Show and also says "It's not a joke", he keeps his gaze turned towards Murray in one shot and towards the audience in the next.
Answer: This is later, as the building appears to be Arkham. He's committed there instead of going to jail based on his insanity. It appears he is laughing about the death of Thomas Wayne, we see a flash of that scene again for a reason.
lionhead