I think a better question is, why hasn't Gotham city killed him? I mean how many people has he killed? It seems unrealistic that a state plagued by that much brutal murderous crime wouldn't have instituted some kind of death penalty. I mean if a serial killer kills HUNDREDS or THOUSANDS of people I find it hard to believe they would just be putting him in a sanitarium...again. Especially given how often he escapes.

Batman shouldn't kill him, that is crossing an authoritarian line. I'm with the watchmen's view of hero's that anybody who is willing to patrol the streets at night killing murderers and rapists probably should not be allowed to have that job. Fighting crime as a vigilante, less morally grey. Being a one man judge jury and executioner, not a good idea.

Then again, serial comics are so out there and make so little sense (Abassador to Iran? What the hell? Really?) that it doesn't really matter in batman's case. If I were Batman in Gotham I'd be "The fuck is goin on here? Ambassador to Iran? Fuck yeah I'm gonna choke a bitch. He's dead...this doesn't even make sense."

And as an odd coincedental side note, I JUST NOW got done watching under the red hood and then saw this topic. I mean what the hell? John Dimaggia did a decent Joker, but I kept hearing Bendor talking which took me out of it a bit. Really Prefer Mark Hammil though.

After what he did to Robin in Under the Red Hood then yeah I would kill him. 

Hecks no! I would ask him where he gets his sweet suit!

No, but I'd murder the fuck out of Robin!

THIS!

I was wondering if anyone would say this and you did.

You are a genius

Hmm, didn't they explore the killing of villains in the DC arc? It ended up with super heroes controlling the world government, because they have the power to judge what is right and wrong.  I don't really follow DC universe at all so I have no idea, but it isn't batman duty to kill people, only stop them. The city can worry about the individuals and what to do with them, when they are caught.

Yes it was Kingdom Come.  It was great to say the least.  Though Batman didn't kill the Joker.  Can't remember who did.  Still poor Shazam.

No, Because if i was Batman Then I would Be batman And i would do Batman things. Batmen do not Kill Jokers.

Magog killed the Joker (and Joker had this "What kind of shit is THIS!?" look on his face.  Superman was so hurt by people thinking Magog was a hero that he quit.  Magog regretted it, too.

ya probably