There is a question that arises in my mind from watching this exceptional film. To me it is one of the unsettling undercurrents of Sling Blade. If any of us had experienced the childhood of Karl Childers, would we have become much different? Is his mental and emotional "retardation" a product of nature or a complete lack of nurturing? As we watch him tell the tale of his life before entering into the state hospital, the psychological puzzle unravels in a most disturbing fashion.
Karl's parents made him sleep out in the shed on a dirt floor. They fed him "pretty regular" but the only passage that can be interpreted as any form of kindness is when he mentions that they brought him biscuits three or four times a week. Karl loves those biscuits, they became something of an oasis to him in his childhood. The desert surrounding that oasis consisted of his mother giving him regular Bible lessons as her only interaction with him, being taunted and abused on the few occasions he went to school, and never being allowed to come into the house. The most heart-rending story comes as he describes his brief interlude with his "little brother." His parents bring him a bloody blanket and tell him to throw it away. Unwrapping the blanket, Karl finds a tiny fetus, still alive but not long for this world. He decides to bury the "little feller" but during his confession to Frank, he wonders if maybe there was something he could have done to save his life.
At the age of 12, Karl hears noises up in the house and goes up to investigate. He sees Jesse, a local boy who has been his main abuser in school and around town, on top of his mother. Believing that Jesse has forced himself upon her, Karl picks up a kaiser blade (some folks call it a sling blade) and kills Jesse. To this Karl's mother responds with "What'd ya kill Jesse for?" Incensed by the realization that his mother was in favor of what Jesse was doing, Karl kills her as well. Thus begins Karl's years of being institutionalized.
During the interview prior to his release from the state hospital, Karl makes a statement that is a well placed bit of foreshadowing. Will he ever kill someone again? "I reckon I got no reason to kill no one."
The outside world is overwhelming to Karl, who would rather remain in the confines of the state hospital. Upon trying to get back in, he is told he cannot return because he is "well." Jerry, the doctor who has overseen Karl's years in the hospital, works to find him a job doing small engine repairs. All seems okay, as Karl lives in the back and discovers a new taste treat, "french fried potaters."
The next undercurrent comes from the fact that Karl has never loved or been loved. He finds love in the friendship of Frank, and Frank becomes the most important thing to him in the world. He becomes accepted by Frank's mother, Linda, who is a widow ensnared in a maddeningly empty relationship with Doyle (who is played with amazing precision by Dwight Yoakam). Doyle, you see, hates "homosexuals, mental retards and wimpy kids." Guess what, Linda has "one of each." Frank and Karl are joined by Vaughan (John Ritter), an easy going dollar store owner who struggles with his homosexuality amidst the limits of the small town mentality. They are Linda's support system while Doyle's abuse of them all keeps anyone from being happy or feeling in any way secure.
Frank's confession to Karl that he wishes Doyle were dead causes Karl to have an intense moment of realization. To kill Doyle would allow everyone to have what they want, including Karl himself. His thinking is utilitarian in this way, and even his study of the Bible produces the realization that he has already committed the sin of murder, so he is already earmarked for "Hades." To kill Doyle will give Frank the peace and happiness he desires, liberate Linda (who, after all, is nice enough to make Karl biscuits and gravy at four o'clock in the morning), and beyond that... give the state reason to put Karl back in the institution, which is where he would rather be. The world outside is "too big" for Karl.
Evaluate the story in any way you wish, there are so many different angles from which to view the story. That is one of the reasons it is a great film. In the end you can neither condemn Karl, nor truly applaud him. Everything in the movie is so understated and haunting, and nothing highlights this fact more than the scene late in the movie where Karl is trying to fish a little bit of mustard out of an empty jar to put on his biscuit as he sits alone in the kitchen... waiting.