Matthew McConaughey stars in William Friedkin’s Killer Joe. Courtesy of Voltage Pictures.

For a while, it seemed like all Matthew McConaughey could play were variations on his sleazy stoner role in “Dazed and Confused.” His aspirations to be taken seriously as an actor were in the distant past. Over the last decade, McConaughey seemed perfectly content in coasting on his photogenic looks and slick posturing wrongly mistaken for charm. He wasn’t an actor–he was a walking midriff.

It wasn’t until last year’s thriller, “The Lincoln Lawyer,” that an unmistakable urgency started to creep back into McConaughey’s performances. Perhaps this was spurred by the talent-packed ensemble that surrounded him (Marisa Tomei, Bryan Cranston, William H. Macy, to name a few). Or perhaps McConaughey was finally done with his extended vacation on the beach and was ready to come back to work. A possible comeback was further evidenced in the actor’s acclaimed work in Steven Soderbergh’s surprise crowd-pleaser, “Magic Mike.” But it’s in William Friedkin’s galvanizing adaptation of Chicago theatre icon Tracy Letts’s play, “Killer Joe,” that McConaughey leaves no shadow of a doubt that he is not only back in top form, but currently surpassing all of his previous screen work. Oscars are never granted to pictures like “Killer Joe,” but I doubt there will be a better performance this year.

“Killer Joe” gained a notorious reputation in the theatre community ever since it made its stage debut back in 1993. Letts was a young, untested playwright bursting with energy and audacity when he wrote this grisly little satire about an obscenely dim-witted family of slackjaws that make the stupid decision to do business with a shady contract killer. It’s difficult to imagine watching “Joe” performed in an intimate venue like the Profiles Theatre. Letts’s graphic depiction of sex and violence is shocking, but only to a point. If the audience actually cared about any of these characters, “Joe” would be borderline unwatchable. But since they’re all idiotic caricatures portrayed by A-list actors with a sense of deadpan desperation, the audience ends up cackling all the way up until they reach their unseemly fate. Like the bumbling antiheroes in a Coen Brothers film, the Smith family makes a deal with the devil and ends up paying dearly for it. Joe carries out his sick vision of justice in ways both excruciatingly brutal and darkly comic. I can’t remember the last time a film made me want to laugh, groan and vomit–simultaneously.

Emile Hirsch has an inherently engaging screen presence, but his character here is so profoundly moronic that audiences might feel inclined to smack him with a 2×4. Neck-deep in life-threatening debt, Hirsch is in need of instant cash. When he discovers that his mother’s life insurance policy is worth $50,000 (thanks to a tip-off from his mother’s ex-boyfriend), he hires Joe (McConaughey) to bump her off. Apparently, Hirsch’s helplessly dumb pop (Thomas Hayden Church) and sweetly virginal sis (Juno Temple) have no qualms with this plan. Even his stepmom (Gina Gershon) supports him, though she silently harbors doubts that he’ll actually be able to pull it off. It doesn’t take long for Joe to size up the family’s combined IQ level and proceeds to get precisely what he wants, no matter what the cost.

Gershon deserves some sort of award for tackling the film’s NC-17-rated sequence involving a drumstick that nearly does as much damage to the fried chicken business as Chick-fil-A. Temple’s utter lack of inhibitions (previously displayed in Gregg Araki’s oddball charmer, “Kaboom”) make her an ideal fit for the role of the deflowered innocent, and her beguiling features are all the more refreshing when juxtaposed with the grime and gore. Church delivers his funniest work since “Sideways,” and proves to be the only actor capable of stealing scenes from the top-billed star. But this is McConaughey’s show through and through. After playing a series of dense surfer dudes, it’s great to see him inhabiting the skin and psyche of the smartest man in the room, though it’s not like “Joe” gives him much competition in that arena.

Unlike Friedkin’s self-righteous exploitation classic, “The Exorcist,” this film isn’t attempting to make any grand statements, and the director appears to be relishing the sheer extremity of the material (he also helmed the film version of Letts’s “Bug”). While many audience members may consider themselves desensitized by the onslaught of sex and violence in modern cinema, they may be surprised by just how much Friedkin can make them squirm. Some viewers will leave feeling offended and repulsed, and they have every right to feel that way. But for those brave few seeking the guiltiest of guilty pleasures, “Killer Joe” is a knockout.

Wanna see McConaughey’s other great screen performance? Check out Jill Sprecher’s 2001 gem, “Thirteen Conversations About One Thing.”