Some Folks Call It a Sling Blade (1994)

Twenty-five years after commiting a double murder, Karl Childers is going to be released from an institution for the criminally insane. A local reporter comes to talk to him, and after some fussing about her gender, the institution's director lets her talk to Karl (after all, he'll have to talk to women after his release). Karl talks about his life leading up to the crime, and the reporter listens in horror.