KilroywasNOTHere
"BEEP!"
We know batman for whatever reason however impratical will not kill the joker, however if the US government decided to hired deathstroke, deadshot, or even Lobo to either kill the joker outright or even capture him so that Joker can be tried outside of gotham and sent to good ol fashion "don't drop the soap." Federal prison (Where let's face it, joker would last a week max) would batman still try to stop the merc so he can bring the joker to justice "the right way" or would he simply walk away and say "Hey If this is federal business don't let me stop you." followed by a pouring of the bubbly while celebrating the soon inevitable end of the greatest thorn in his side.
Frankly I can sadly see both scenarios occurring depending on how you write Batman. Frankly if it were me I'd simply let the bounty hunter go on his merry way or even offer to help, followed by celebrating. Then again, I would have killed the Joker after the first three 9/11 esque massacres he caused even if it meant I needed to retire from the batman role for a bit.
Frankly I can sadly see both scenarios occurring depending on how you write Batman. Frankly if it were me I'd simply let the bounty hunter go on his merry way or even offer to help, followed by celebrating. Then again, I would have killed the Joker after the first three 9/11 esque massacres he caused even if it meant I needed to retire from the batman role for a bit.