Vincent Kartheiser

“Alpha Dog” is a true-crime story inspired by a pipsqueak thug improbably named Jesse James Hollywood, who once reigned over a modern Sodom and Gomorrah in - you know it - Los Angeles.

In 2000 Mr. Hollywood, a 20-year-old fledgling marijuana kingpin, allegedly ordered the murder of the 15-year-old Nicholas Markowitz, whose half brother owed $1,200 for a dope debt. Friends of this alpha dealer kidnapped the teenager while he was walking near his San Fernando Valley home. Initially constrained, the hostage was soon getting stoned, drinking and watching television with his captors, who even brought him along to a party. At some point, however, Mr. Hollywood awoke to the severity of the crime (he called his lawyer) and decided to get rid of Nicholas, who was shot multiple times and left to rot in a national forest with sweeping ocean views.

Mr. Hollywood then fled the country and spent years as one of the F.B.I.’s most wanted, before being captured in Brazil in 2005. By then the writer and director Nick Cassavetes was deep into “Alpha Dog,” his sexed-up, alternately funny and horrifying, heavy-panting exploitation of the crime, which, despite some name and geography changes, tracks close to the recorded facts.

Here the dimwitted mastermind is Johnny Truelove (Emile Hirsch), a pint-size nihilist with wary eyes and a face full of molting hair. He has a skinny blonde named Angela (Olivia Wilde), a pit bull called Adolf and a posse of cretins. He lives in a ranch house big enough for the Bradys and watches a lot of TV. Bruce Willis plays his dad.

The cretins rule in “Alpha Dog,” which has much the same entertainment value you get from watching monkeys fling scat at one another in a zoo or reading the latest issue of Star magazine. Of course a little of that nasty stuff may land on you, but such are the perils of voyeurism. Voyeurism that Mr. Cassavetes, a filmmaker with a lurid imagination and a talent for coaxing full-throttle performances from his actors, rewards with an embarrassment of vulgarities: lusciously tanned flesh, sensuously quivering muscles, cascades of blond hair, acres of tattoos, a sylph in a schoolgirl miniskirt (“Dance, bitch!” someone cries), a three-way in a swimming pool, intimations of Nazism, a little tae kwon do and a lot of homegrown weed.

The kids are not all right. Which is, like, you know, the point. Maybe yes, maybe no, or maybe it’s just fun to watch a lot of attractive, talented young actors shimmy across the screen while embodying the collective parental nightmare. Do you know where your children are? In “Alpha Dog” they’re getting busy, chilling out, smoking blunts and chugging coolers faster than a toothless wino. They’re also baby-sitting a hostage named Zack (Anton Yelchin). They do the darnedest things, these children of the suburban damned: Johnny’s best friend, Frankie (Justin Timberlake), for one, does his chores and culls buds from his father’s pot plants while wearing low-slung shorts and no shirt, his snaky torso soaking up the rays and our gaze under the bright blue sky.

Frankie is as dumb as a bowl of beans, which invests him with an air of harmlessness that grows progressively more frightening as the hostage crisis deepens. Adorned in tattoos, Mr. Timberlake holds the screen effortlessly, delivering a gestural performance that, whether he’s loping across a room or executing a goofy little dance for his buddies, legs rapidly slicing back and forth, reveals as much about Frankie - his need to please, his need to perform - as his lines. Mr. Timberlake’s transformation from pop-culture joke to born-again idol seems more than just smart public relations and a recent well-executed stint on “Saturday Night Live,” and it should earn another boost when and if Richard Kelly’s latest film, “Southland Tales,” is released in theaters.

Ben Foster’s nervy, wonderfully far-out performance as Truelove’s nemesis, Zack’s brother, Jake, is even more notable because it pushes up against the edge of credibility. Like most of the guys and some of the girls in the film, this bullet-headed tough is covered in inky designs, the difference being that he has some Hebrew letters tattooed on his chest and two lightning bolts etched on the back of his neck. Jake looks like the younger brother of the Jewish neo-Nazi Ryan Gosling played in “The Believer,” but despite the Hitler poster and the “Sieg Heil” salute from his girlfriend (a terrific Heather Wahlquist), it’s impossible to know where he’s coming from other than Planet Freak. The film doesn’t say much about him - or anything else, really - but Mr. Foster gives plenty.

Mr. Cassavetes does make some regrettable choices in “Alpha Dog,” notably a news crew that pops up whenever he seems to hit a narrative rough patch. He also puts Sharon Stone in a monstrous fat costume for some flash-forwards, nearly undoing the fine work she does in earlier scenes as the kidnapped boy’s distraught, overprotective mother.

In interviews Mr. Cassavetes has tried to suggest that “Alpha Dog” is about lousy parenting. What rot. “Alpha Dog” is about the pleasure of watching beautiful bodies at rest and in motion. It’s about the allure of youth, the erotics of violence and the inevitable comeuppance that must always be meted out whenever youth strays too far from the fold and another sad case becomes an evening’s entertainment.

“Alpha Dog” is rated R (Under 17 requires accompanying parent or adult guardian). It features gun violence, under-age drinking, lots of dope smoking, some sexual scenes and female nudity.