The Joker doesn't have an origin story as such, but Batman's presence being inadvertently responsible for his creation has widely been accepted as the canon for years no, even though only his past as the leader of the criminal Red Hood gang has been touched on in the current DC Comics Universe. Because of this vagueness, Gotham has a lot of creative freedom when it comes to how they decide to tackle The Joker's introduction. Heller has confirmed that Season Two is going to delve into how The Joker came to be, but based on the response to Cameron Monaghan's deranged Jerome in Season One, doing so will be a sure fire way to alienate fans. The actor was suitably creepy and certainly got the laugh right, but to have this early version of The Joker operating in Gotham a decade or so before Batman comes to be just feels... wrong! The Joker's whole reason for existing is Batman, and rushing into telling his origin story so soon means he'll have potentially been terrorising Gotham for years before Bruce Wayne undergoes his transformation into The Batman. While there's a chance they'll take a slow burn approach and keep the make-up and green hair off Monaghan, throwing such a big villain into the mix with important ties to Batman feels like wasted screentime that would be better off going to those other undercooked villains. Based on that interrogation scene in Season One, Jerome is only really missing a purple suit at this point, and The Joker would be much better served for a season a few years from now rather than rushing things.
