Why don’t the citizens of Gotham pass a law to execute the Joker? You’d think they’d catch on after the first few escapes.
I’m surprised the Penguin hasn’t had him killed. After all, Cobblepot is a businessman type villian and surely having a maniac like the Joker running loose is bad for businesses of Gotham, legitimate business or otherwise.
As soon as I had the opportunity I’d simply kill him. How many people has the Joker murdered let alone maimed or injured in the last 10 years of comic book time? Batman needs to stop being such a pansy and snap that guys neck before he has a chance to hurt someone else.
Marc
Oooh! Marc called Batman a pansy! I’m telling!
Ever read The Killing Joke? That explains why not.
Killing the Joker means you’re as much a psychopath as he is.
For the same reason every Villian who has caught the Good Guy doesn’t just shoot the GG’s brains out.
It “kills” future story possibilities.
BRRRRRRRRRRING!
“Hello, this is the Batcave. What? Doomsday? Loose in Metropolis? Killed Superman again? Hold on, I’m on my way.”
VROOOOOOM!
Guy Gardner hangs up the phone. “Sometimes it’s just too easy!” He goes and kills the Joker. Everyone lives happily ever after.
Forget about killing him. Just assume President Luthor commuted his death sentence.
But why the heck don’t they lock the guy up? I mean really lock him up. The guy has no superpowers. You stick him in a big cage, you surround the cage with cameras and guards. And he stays there. I don’t care how crazy or smart or resourceful or whatever he is. He’s not going to dig his way out through steel and concrete with his teeth and fingernails.
Here’s an idea: assign a couple of National Guardsmen to watch his cell at Arkham, restrain him to the bed and dose him with enough anti-psychotics and sedatives to keep him from escaping.
I figger that an armload of Hostess Fruit Pies ought to do the trick.
No, but that’s the origin of Harley Quinn: he’s so good at head games that he can very gradually talk the staff into craziness – and nobody sees it coming, and they engineer his escape.
Or a Kool-Aid Man game for his Atari 2600.
This is the type of question that’s so circular it can get you dizzy. Many of the Joker’s murders (even if the minority) would not qualify for the insanity defense in most states in real life. The only reason the Joker was not executed long ago is the only noted by ftg – it hampers future story potential. That’s the only answer to the question – there is no “on-panel” explanation because in anything approaching a realistic setting, the Joker would be long dead already.
–Cliffy
So you put him in a cell where he can’t talk to the guards. And you rotate them frequently on a random schedule. And you don’t let the guards watching him have control of his cell door.
Stone walls and iron bars do not a prison make - but add in some locks and guards and electronic sensors and alarms and now you’ve got something.
Just get a couple of South Korean Marines who don’t speak english to guard him, then. 
Or you could lobotomize him…see how dangerous he is with an IQ of 64 and barely enough motivation to use toilet paper.*
I still hold to the theory that Batman won’t kill his rogues because it gives him a reason to keep being Batman, though.
*Actually, in that one parallel universe episode of Justice League, lobotomizing him arguably worked better than any other possible psychiatric treatment. Pretty mellow, no visible psychotic tendencies, much less a “danger to himself or others”…he even seemed to be capable of light clerical duties. Which, from a clinical standpoint, seems to be a step up from running around in a zoot suit nerve gassing people for laughs.
Well, maybe if Batman had left well enough alone in the Going Sane storyline we wouldn’t be having this discussion. However…
There are lots of non-fatal options that would also remove the Joker’s danger to society. For example:
-Phantom Zone. Sure, it’s supposed to be for Kryptonian criminals, but at least Joker wouldn’t be a danger any more.
-Uninhabited planet. Superman can still fly between planets, right? Zip out, find some planet with an earthlike atmosphere, dump the Joker (and whoever else, like maybe Lex Luthor) there. No more problem!
-Exile him to the future. DC has time travel: maybe in 30 000 years time they’ll be able to cure him, or at least afford a lock.
-Move him to the Metropolis Asylum for the Criminally Insane. Come on, how many lives must have been lost not because the Joker escaped, but because every time he did, Batman failed to simply call Superman and say “Yo, Big Blue, I…yeah, that’s right…how? Oh, killed seventeen guards with a soup spoon…sure you don’t mind? Thanks! See you in…oh, hi Clark.” I think that Superman should be able to keep the Joker in a rubber room.
I thought the death penalty could not be applied to anyone in an asylum, like for example Arkham. That is the answer to the OP.
Trump up charges about him being a terrorist, then when the public has ceased to pay attention, re-label him an “enemy combatant,” transfer him to Gitmo, and mention to a couple of guards “it sure would be a shame if he slipped in the shower and had such a hard knock to his skull he never woke up.”
Nah, that’d need Dubya to be president. In the DCU, they have President Luthor.
Kinda puts things in perspective, doesn’t it?
It’s been noted that when one person interviews a totally psychotic person, they tend to start identifying with trusting with the looney. That’s why criminal interviews are always done with two agents–to keep each other sane. It always amazes me on TV when any agent is interviewing the nutjob in a small room with just the two of them.
With the Joker, I’d go with four guards.