The maxim that the bad guy is always the best role is one that has to be discovered anew by every generation of Hollywood leading men who hit a brick wall after wearing out their welcome in romantic leads. Matthew McConaughey hit that wall earlier than some: Good-looking he may be, but (in my opinion, anyway) in a creepy way that always felt out of place in comedies. This was not a guy you wanted to see dating your sister.

That’s sort of what he ends up doing in Killer Joe as a murderous sociopath, a role that many actors would have found some way to soften. Joe Cooper is a Dallas detective who moonlights as a killer for hire. His services are sought by the Smiths, a family so low-down that they may be intended as a parody of cinematic white trash.

Son Chris (Emile Hirsch) is a wannabe drug dealer in deep debt to his suppliers. His father Ansel (Thomas Haden Church) is no help: He’s never seen a thousand dollars in his life. He certainly wouldn’t be living in this dump with his slutty new wife Sharla (Gina Gershon) and Chris’ younger sister Dottie (Juno Temple) if he had. Chris’s solution: cash in on his mother’s $50,000 life insurance policy. Of course, for that she has to die, which is where Killer Joe comes into the picture. But because the Smiths can’t meet his down payment, he accepts a retainer: Dottie.

Adapted from an early play by Tracey Letts and luridly directed by William Friedkin, who at 76 is as unafraid to push buttons as he was when he made The Exorcist, Killer Joe is not a movie that will bother McConaughey’s fans: Even if they go to see it without knowing anything about it (ignoring the well-earned NC-17 rating), the plentiful violence and sleaze in the opening scenes alone will send them fleeing the theater. Just as well—it gets harsher as it goes on. You can look at it as a black comic commentary on tabloid entertainment or exploitation of the same genre, though it’s hard to argue the skill with which is has been made and performed. The extended scene where Dottie is delivered to Joe may remind you of the more unsettling parts of Cape Fear, and I’ll bet that McConaughey studied Robert Mitchum’s performance in that film for lessons in slow, quiet menace. Extremely violent and grimly comic, Killer Joe is a movie you’ll love or hate, but one you won’t forget.

Watch the trailer for Killer Joe