Sling Blade

After catching his mother and her boyfriend "in flagrante delicto" and dispatching both of them with a farm implement known as a sling blade, a simpleminded 11-year-old boy is sent to a mental hospital where he spends the next 25 years. Upon his release, the emotionally and mentally stunted man-child returns to his Arkansas hometown and takes a job in a local garage, only to have the past inexorably repeat itself.