Watch Sling Blade
Karl Childers (Thornton) is a mentally disabled man from Arkansas who has been in the custody of the state mental hospital since the age of 12 for having killed his mother and her lover. Although thoroughly "institutionalized", Karl is deemed fit to be released into the outside world. Prior to his release, he is interviewed by a local college newspaper reporter, to whom he recounts the brutal murder of his mother and her boyfriend with a kaiser blade. (During which scene he notes to the reporter that, "Some folks call it a sling blade; I call it a kaiser blade," the line from which the film derives its name.) Karl continues, saying that he killed the man because he thought he was raping his mother. When he discovered that his mother was a willing participant in the affair, he killed her too. Having developed a knack for small-engine repair during his childhood and incarceration, Karl lands a job at a small-engine repair shop in the small town where he was born and raised. Around this time, he befriends young Frank Wheatley (Lucas Black). Karl shares with Frank some of the details of his past, including the killings. Frank reveals that his father was killed - hit by a train - leaving him and his mother on their own (he later admits that he lied, and that his father committed suicide). Frank introduces Karl to his mother Linda (Natalie Canerday), as well as her homosexual friend Vaughan (John Ritter), the manager of the dollar store where she is employed. Despite Vaughan's concerns about Karl's history in the mental hospital, Linda allows Childers to move into her garage, which angers Linda's abusive boyfriend Doyle (Dwight Yoakam). Eventually, Karl bonds with both Linda and Vaughan. In an early scene, Vaughan tells Karl that a gay man and a mentally challenged man face similar obstacles of intolerance and ridicule in small-town America. Karl quickly becomes a father figure to Frank, who misses his father and despises Doyle. For Karl, Frank becomes much like a younger brother. Karl eventually reveals that he is haunted by the task given him by his parents when he was a child of six or eight years: To dispose of his premature, unwanted, newborn brother. In a subsequent scene, he visits his father (Robert Duvall) and tells him that killing the baby was wrong. Karl further reveals to his father that he used to think about killing him, but eventually decided he wasn't worth the effort. Doyle soon becomes increasingly abusive toward Karl and Frank, leading to a drunken outburst and physical confrontation with Linda and Frank. Although Linda initially kicks Doyle out of the house, she quickly reconciles with him. Sensing the recapitulation, and knowing that he has the upper hand again, Doyle confronts Karl and Frank once more, announcing his plan to move into the house permanently, and that big changes are afoot as a result, including the removal of Childers from the house. Karl begins to realize that he is the only one who can bring about a positive change and spare Frank and his mother a grim fate. Karl makes Frank promise to spend that night at Vaughan's, and asks a favor of Vaughan to pick up Linda from work and have her stay over, as well. Later that evening, Karl returns to Linda's house. He seems to have second thoughts at first, and walks away from the house for a time, but then retraces his steps, and enters the house. After asking Doyle how to reach the police by phone, he promptly kills him with a blow from the lawnmower blade he'd sharpened for the task earlier that day. He then turns himself in, calling the police and requesting a hearse be sent, per Doyle's direction. He calmly dines on mustard and biscuits while waiting to be returned to the state hospital. Once at the state hospital, he seems to have reached a turning point and peace of mind, sternly rebuffing a sexual predator (JT Walsh) at the hospital who used to use him as a captive audience for tales of his horrible deeds.