Jack Napier (Earth-1: Pre-Crisis)

"Batman brought out all the crazies in Gotham. If it weren't for him, there wouldn't have been a Joker!"

- Jacob Kane

Jack Napier, better known as the Joker, was a notorious criminal in Gotham City and an inmate at Arkham Asylum.

Early life
At some point, Jack Napier became a criminal in Gotham City and an enemy of Batman who went by the alias, "Joker".

Prosecution
He was later prosecuted by assistant district attorney Angus Stanton and sent to Arkham Asylum.

Trivia

 * A fictional version of the Joker was played by Heath Ledger.