We know The Joker is the main villain of "The Dark Knight." "Batman Begins" already suggested that. But the casting of Eric Roberts as a Gotham City Mafioso suggests more to the story. Roberts confirmed that he would have scenes with both Christian Bale as Batman/Bruce Wayne and Heath Ledger as The Joker, and his moral alignment is no question.
"I have interactions with both those guys and I am a bad guy," Roberts said. "I love Christian Bale. What an actor."
Beyond that, even Roberts doesn’t know the extent of his villainy. "All I can tell you is I’m a Mafioso in Batman and I have not even seen the script. I’ve only seen the pages, they gave me two to audition with. It’s all very hush hush."
Roberts also just joined the cast of "Heroes" as HRG’s boss, Thompson. Now he’s a comic book aficionado. "It was thanks to Heroes I think that I started to get this newfound appreciation because Heroes is basically a comic book."
