THUG 1: Five stories. Straight down. There wasn't no blood in the body.
THUG 2: No s***. It was all over the pavement.
If what these thugs say is to be believed, Batman is a violent vigilante throwing people off buildings. Do you think they are telling the truth, or have Batman's methods of vigilante justice been exaggerated as rumors continue to spread?
BATMAN: I'm not going to kill you. I want you to do me a favor. I want you to tell all your friends about me.
What Batman does here contradicts the thugs' believe that Batman chucks men off buildings. It seems here that his method of vigilante justice is to strike fear into hearts of his enemies.
MAYOR: The festival opens. The police are gonna stop these gangsters.
The mayor talks a big talk, but he doesn't walk the walk. What makes him so ineffective? He seems to be more focused on having a parade than in getting the police to do their jobs.
JOKER: You made me, remember? You dropped me into that vat of chemicals! That wasn't easy to get over! And don't think that I didn't try.
BATMAN: I know you did. You killed my parents. […] I made you, you made me first.
JOKER: Hey, bat-brain, I was a kid when I killed your parents. When I say I made you, you gotta say you made me. How childish can you get?
Do you think Batman thinks it is justified to kill Joker because he killed his parents? If Batman considers it justice to kill Joker, does that make him any better than Joker?
MAYOR BORG: Public safety in Gotham City is no longer a laughing matter.
The Mayor makes a pun after Batman rids Gotham of Joker and his henchmen. Maybe if he took his job a little more seriously, the crime wave wouldn't have risen in the first place.
GORDON: He gave us a signal.
The Bat Signal is Batman's way of promising to continue bringing criminals to justice in Gotham City. This movie is pretty much an origin story, not of Batman, but of the Bat Signal.