In the first season of Gotham, Jerome, a circus performer's son and her killer, has gone off the deep end since found out by the GCPD. He under goes the alias Jack White a new crime lord in Gotham City in the future 2nd season until hurled by Kevin Bacon's Batman by accident into a chemical vat that reincarnates him as The Joker. Jerome Jack White he formally is now known as the infamous crime clown or clown prince of crime (The Joker) terrorizes Gotham in its 2nd season fall 2015.
Jared Leto on the other hand will be playing the crime clown in the DC Cinematic Universe esp. in the future movie Suicide Squad when it storms theaters summer 2016.