Some directors mellow in their old age; not so William Friedkin, as his grisly and grimy take on Tracy Letts’ grand slice of southern gothic Guignol shows.

Friedkin’s controversy-baiting style has won him an army of devotees and led to a back catalogue that many filmmakers would sell their soul for. The French Connection (1971) and The Exorcist (1973) have rightly earned their place in cinema’s Valhalla, while pictures like Sorcerer (1977), Cruising (1980) and To Live And Die In LA (1985) may be lesser known, but are equally absorbing.

He made a welcome return to horror in his disturbing 2007 adaptation of Letts’ suffocating play Bug and collaborated again with the celebrated playwright four years later for what, according to the poster, is “a totally twisted deep fried Texas redneck trailer park murder story”.

The film centres around the Smith clan, a less-than-functional trailer trash brood who make the family from The Texas Chainsaw Massacre look sweet in comparison. Chris (Emile Hirsch) is a drug dealer who’s got himself into debt with the wrong people and, with the help of his simple-minded dad Ansel (Thomas Haden Church), makes a pact with the devil in the shape of Mephistophelean hitman-cop Joe Cooper (Matthew McConaughey) to murder his mother and collect on the life insurance.

Chris is unable to provide a down-payment to the dark and mysterious Joe, who decides instead to take a retainer in the form of Chris’ childlike sister Dottie (Juno Temple) until the cash is forthcoming.

Friedkin has never been one to shy away from down and dirty filmmaking and is at his most gleefully scuzzy here in what’s effectively a good old-fashioned exploitation B-movie. There’s something of the 1980s here, especially in the montage of close-ups as we’re introduced to Joe, who’s such a badass even the chained-up psycho dog sat outside the family trailer goes quiet when he strolls past.

Furthermore, a pretty good clue of what to expect comes early on when the first sign we get of Chris’ loathsome stepmother Sharla (Gina Gershon) is of her naked from the waist down. Subtle it ain’t.

The film’s blackly comic tone adds fuel to the argument that Friedkin is mocking the characters; the only one who seems remotely redeemable is Dottie, although you’re left with the sneaking suspicion she knows more than she’s letting on.

Killer Joe has been likened to a fairytale, with Dottie as the princess looking for her Prince Charming and Joe the wolf at the door, yet no-one emerges from this particular tale with a happy ending. The Smiths’ murderous greed and back-stabbing comes back to bite them hard as the evil they’ve invited into their home arrives for its pound of flesh in the film’s closing scenes, most notoriously involving a fried chicken drumstick.

The film is held together by McConaughey’s shark-eyed turn as Joe, who glides around like some Stetson-wearing angel of death and remains unnervingly calm until his thirst for violence takes over.

Killer Joe certainly isn’t to everyone’s tastes, but for those who enjoy their movies trashy it’s finger lickin’ good.