Robert Pattinson didn't set out to play Chris Hansen in "Primetime." But somewhere along the way, it just became "irresistible." "I was trying to mold the part to be the best part to play for somebody else, and then I got more and more attached to it," Pattinson said Saturday at the Venice Film Festival, where the film is having its world premiere.

The 40-year-old English actor started out as a producer on the film about the NBC Dateline show "To Catch a Predator." But while he and his collaborators found that they couldn't help but imitate Hansen while chatting about the project, he "found his accent very difficult." "This more than any other part that I've done, just grunt work," Pattinson said.

He was also part of the reason directing duties went to Lance Oppenheim, who had only directed documentaries up until this point.