Sling Blade (1996)

A mentally disabled man released from a mental hospital fights to protect a boy and his mother from an abusive stepfather

After spending most of his life in a mental hospital for a double murder committed as a child, Karl Childers is finally released. Trying to live quietly, he forms a close bond with a boy and his mother, but when the boy’s dangerous stepfather becomes a threat, Karl steps up to defend the family.