The movie is based on the hugely successful graphic novel
The Killing Joke was a one-off graphic novel released in 1988, written by the hugely influential Alan Moore (Watchmen), and is perceived by many to be the ultimate Batman / Joker storyline.
As the superhero movies became more and more successful, the chances of an actual adaptation of The Killing Joke coming to fruition seemed less and less likely, thanks to the stories explicit, over-the-top violence.
However, the team behind the much celebrated Batman: The Animated Series have taken over the project, and the first trailer for the movie has just been released.
Featuring the voice-work of Kevin Conroy as Bruce Wayne/Batman and Mark Hamill as The Joker, it tells the story of The Joker's endless attacks on Commissioner Gordon and his family, in an attempt to push the righteous Gordon over the brink into insanity, and Batman's attempts to stop him.
Batman: The Killing Joke is due for release this July.