"The worst part about having a mental illness is that people expect you to behave as if you don't."
Murray: You can say that again, pal!
Murray: Who's there?
Joker: It's the police, ma'am! Your son's been hit by a drunk driver. He's dead!
Arthur: ...I had a bad day.
Murray: Okay. I'm waiting for the punchline.
Joker: There is no punchline. It's not a joke.
Joker: Come on, Murray. Do I look like the kind of clown that could start a movement? I killed those guys because they were awful. Everybody is awful these days. It's enough to make anyone crazy.
Murray: Okay. So that's it, you're crazy. That's your defense for killing three young men?
Joker: No. They couldn't carry a tune to save their lives.
[The crowd boos and jeers]
Joker: Oh, why is everybody so upset about these guys?! If it was me dying on the side-walk, you'd walk right over me! I pass you every day, and you don't notice me! But these guys — what, because Thomas Wayne went and cried about them on TV?!
Murray: You have a problem with Thomas Wayne, too?
Joker: Yes, I do. Have you seen what it's like out there, Mur-raaay? Do you ever actually leave the studio? Everybody just yells and screams at each other. Nobody's civil anymore! Nobody thinks what it's like to be the other guy. You think men like Thomas Wayne ever think what it's like to be someone like me? To be somebody but themselves? They don't. They think we'll all just sit there and take it like good little boys! That we won't werewolf and go wild!
Murray: You finished? So much self-pity, Arthur. You sound like you're making excuses for killing those three young men. Y'know, not everybody — and I'll tell you this, not everyone is awful.
Joker: ...You're awful, Murray.
Murray: Me? I'm awful? Oh, yeah, how am I awful?
Joker: Playing my video. Inviting me on the show. You just wanted to make fun of me. You're just like the rest of 'em!
Murray: You don't know the first thing about me, pal. Look what happened because of what you did. What it led to. There are riots out there. Two policemen are in critical condition— [Joker begins to laugh] And you're laughing. You're laughing. Someone was KILLED today because of what you did.
Joker: I know! [beat] How 'bout another joke, Mur-raaay?
Murray: No, no, I think we've had enough of your jokes!
Joker: What do you get —
Murray: I don't think so.
Joker: — when you cross —
Murray: I think we're done here now, that's it.
Joker: — a mentally ill loner, with a SOCIETY, that ABANDONS him, AND TREATS HIM LIKE TRASH?!
Murray: Call the police, Gene, call the police.
Joker: I'LL TELL YOU WHAT YOU GET! You get what'cha FUCKING DESERVE!
[Joker whips out his gun and shoots Murray in the head.]
Joker: I know. Isn't it beautiful?
Psychiatrist: What's so funny?
Joker: ...I was just thinking of a joke.
[Scene cuts to little Bruce, standing in horrified shock at the corpses of his parents.]
Psychiatrist: You wanna tell it to me?
Joker: You wouldn't get it.