Understanding is an elastic word, meaning knowledge but implying sympathy, and the friction between these two things is what powers Beautiful Boy, an assured debut feature by writer-director Shawn Ku that, unfortunately, closed Thursday at River East 21. Bill (Michael Sheen) and Kate (Maria Bello), a professional couple preparing to separate after two decades of marriage, are thrust into a nightmare when their only son, Sam (Kyle Gallner), kills 20 people and then takes his own life in a college shooting rampage. This tragedy isolates Bill and Kate from the world as they hide out from the media, then turns them violently against it. The parents grieve for their son but can’t begin to grasp how he could have done such a thing; the people who harass them and the commentators they fearfully sample on TV have no mercy but plenty of ideas about why the young man went berserk.

To deny us our own snap judgments, Ku wisely limits our exposure to Sam. He appears mostly at the beginning of the movie: joggling video footage shows him frolicking at the beach as a boy while, in voice-over, the grown Sam reads a mournful poem about the visit to his English class. When Ku cuts to the classroom, the other students stare in boredom; one guy draws on the side of his high-tops with a pen. That night, looking ashen and tearful, Sam calls his parents from his dorm room. Bill chats with him for a minute and signs off with, “Don’t study too hard.” On the other line, Kate tries to sympathize with his freshman blues, telling him, “All your friends are going through the same thing.” But Sam’s next remark is so puzzling it suggests he’s in a world all his own: “Did you know snowflakes always have six sides?” It’s something he heard in a class, but he can’t articulate what it means to him. The conversation grinds to a halt, and Kate is visibly pained as she signs off, countermanding her husband’s advice: “Study hard.”

The next morning Bill and Kate are confronted with the impossibility of ever understanding Sam when he goes into an early class (presumably the one where he read his poem) and opens fire. There’s a horrible moment in the family home when Kate hears the doorbell ring and sees the shadows of two policemen outside, and her immediate reaction to Sam’s crime is denial. “Liar!” she screams at the cops, doubling over in pain, and even after they’ve gone she insists there must be some mistake. Throughout the movie she and Bill each pass through a stage of grasping for answers, only to give up and pull back again. Sam makes two more brief appearances, in a ranting farewell video he’s sent to the media and, much later, in a private video he’s mailed to his parents, in which he apologizes and implores them not to hate him. But not even this last gesture on his part brings Bill and Kate any closer to fathoming the unfathomable.

Given the roiling emotions at play, Ku is admirably calm and observant, focusing on the practical details of the parents’ bizarre situation and noting the hermetically sealed world in which they find themselves. Once Sam’s name is released to the press, news vans collect in front of the house and the couple hide upstairs; finally they steal away in the middle of the night to stay with Kate’s brother, Eric (Alan Tudyk), who’s married and has a little boy of his own. Bill insists that they release a statement of sympathy for the victims, though Kate is incensed by the idea; he goes on television alone to read it, and she goes into the morgue alone to identify the body. When he busies himself with calling the bank to close out Sam’s student loan, she accuses him of trying to “erase” their son. They could both use something to distract them, but when Bill calls his workplace he learns he’s been given four weeks of paid leave—ostensibly to help him recover, but mostly to keep him out of the office as camera crews roam around looking for him.

For both parents, grief curdles into rage as they realize the outside world hasn’t the least sympathy for them or their dead boy. Whenever I see someone in a movie turn off TV coverage of himself, I never believe it—if I were on TV I’d watch the whole thing, no matter how bad. But in this case Bill and Kate seem completely credible as they flinch from the TV set and the computer screen. In a darkened room at her brother’s house, Kate investigates Sam’s Facebook page and finds it crammed with hateful messages. Bill makes the mistake of channel surfing and lands on a Glenn Beck-style commentator who insists the killer’s parents are the real culprits: “We should find them, whatever rock they’re hiding under!” In one of the most shocking scenes, Bill goes back to check on their house one night and finds a young burglar pawing Sam’s personal things as he joshes with a friend on his cell phone. Enraged, Bill chokes the kid, then catches himself and allows the intruder to flee. The kid’s parting shot—”Fucking psycho!”—lets Bill know that he has no rights anymore.

Through all this the question of what made Sammy kill keeps coming up again and again, from every quarter. “Did we do something?” Kate asks when the horror is still fresh. “Did we not do something?” When Kate’s little nephew asks her if Sam was bad, her reply is simple: “Sometimes good people do bad things by mistake.” Eventually, as Bill and Kate begin to accuse each other and the details of their unhappy marriage emerge, a workable explanation takes shape: Bill was distant, Kate was smothering. But the more they push toward an answer, the farther away it seems. Near the end of the film, when the couple have separated and Bill is staying at a motel, he confesses to the sympathetic office manager (Meat Loaf Aday) how he cut short his last conversation with Sam. “Why did he call, and what did he want to say?” he now wonders. “He must have been asking for help. He must have wanted us to stop him.” But Sam has taken all those answers with him.

Beautiful Boy shows earmarks of a beginning filmmaker: some scenes are a little too pointed, particularly the one in which Kate, looking for answers, remembers a Christmas party at which she pressured her young son to sing for the assembled guests and he broke down in tears. Like the ignored poem in the first scene, this seems like a pathetic excuse for a massacre, but it’s the best Kate can come up with. Ku demonstrates a wisdom beyond his years, though, when he suggests that Bill and Kate might yet be united by the tragedy, if only because shared experience is such a powerful bond. “There just aren’t a lot of people out there who can understand what you’re going through,” observes the couple’s maid. They say there’s nothing more painful than losing a child, but in one sense husband and wife have been given a rare gift: the ability, after all these years, to feel for each other again. 

E-mail J.R. Jones at jjones@chicagoreader.com.