Matthew McConaughey is scarily intense as the title figure, a Texas police detective-cum-hit-man who draws a trailer trash family into a sleazy and deadly pact.

In debt to a local gangster, Emile Hirsch’s good-for-nothing loser wants Joe to murder his estranged mother for the insurance money.

His sluggish father (Thomas Haden Church) and tarty stepmother (Gina Gershon) go along with the scheme, but things begin to unravel messily after Joe demands Hirsch’s sister (Juno Temple) as a ‘retainer’.

Adapted from the stage play by Tracy Letts, Killer Joe proves that veteran director William Friedkin (The French Connection, The Exorcist) still has the ability to shock.

The unflinching sex and violence will be a turn off for many, although those viewers not cowering behind their hands will pick up a streak of dark comedy running through the film.

But it’s the terrific performances that really make this thriller stand out. Hirsch, Church and, particularly, Gershon push themselves to the edge, Temple (daughter of British director Julian) is a revelation and McConaughey, menacing from the start and then increasingly unhinged, is an eye-opener.