The next animated feature from DC Entertainment will be Batman: The Killing Joke, an adaptation of the controversial and acclaimed 1988 graphic novel by Alan Moore and Brian Bolland. Today at Wizard World Comic Con New Orleans, Executive Producer Bruce Timm (Batman: The Animated Series) revealed that they've had to add story to make The Killing Joke a feature-length film and when it will debut.

"The one big difference about it, as opposed to those other projects (The Dark Knight Returns Part 1 & Part 2), is The Killing Joke... the source material is really not long enough to make an entire feature film out of," Timm told ConTV. "So we actually had to add a lot more story to it. Which is tricky. But I think we came up with a really good solution on how that worked."

He added, "We're actually going to be premiering it at San Diego Comic-Con." SDCC runs from July 21–24. Listen to Timm's comments in the video below.