Finally...Joker die....

Only for Batman lovers:

You can't rehabilitate the Criminally Insane. You must wipe their existence from the face of the earth

Just Like the saying goes, "sacrifice one, to save many".

• Batman will never killed The Joker ya know.... he never has the guts to do that....

In The Killing Joke graphic novels, he's trying to 'discuss' this matter with Joker on Arkham Asylum. Here's some of his word;

"I've been thinking lately. About you and me."
"About what's going to happen to us, in the end."
"We're going to kill each other. Aren't we?"

"Perhaps you'll kill me. Perhaps I'll kill you. Perhaps sooner. Perhaps later."
"I just wanted to know that I'd made a genuine attempt to talk things over and and avert that outcome. Just once."

"Are you listen to me? It's life and death that I'm discussing here."
"Maybe my death... maybe yours."

"I don't fully understand why ours should be such a fatal relationship, but I don't want your murder on my... hands..."

Although he was actually talking to the fake Joker since the real Joker already escaped from Arkham but you can see he really don't want to kill The Joker.

And..... on The Dark Knight Returns graphic novels, while trying to captured The Joker, The Joker demand Batman to kill him.
Which Batman refused, and to cut it short, before the police arrived, The Joker twist his own neck and die. He set his body on fire after he 'killed himself'. Not sure how he do that, but this is The Joker we're talking about.
He do that to put the blame on Batman. He wanted the police to think that Batman killed him.
He wanted to make Batman as the bad guy... a villain... and not a hero like everyone else think....
My point is, Batman will never kill The Joker.... and any other villain or criminal on purpose. It's against 'his rule' as stated by Sal Maroni in The Dark Knight movie.