Dirty Harry had no qualms when it came to vigilantism, while Garry Oldman’s DEA agent Stansfield in Leon (1994) was happy to knock off the family of the man who undercut his supply of cocaine.
The Departed (2006), L.A. Confidential (1997), Internal Affairs (1990), Serpico (1973), Touch of Evil (1958) – the Bad Cop is a genre unto itself.
But it is The Bad Lieutenant (1992) starring Harvey Keitel as the Lieutenant (his name is never revealed) that Filth most closely resembles.
Bad Lieutenant is well worth seeing, but be prepared to be shocked and more than a little revolted (and not just at Keitel’s full frontal nudity).
What’s remarkable about both films is how far both Keitel’s and James McAvoy’s characters fall, and they both start from no great height.
Drugs, booze and prostitutes are all on the menu, and in copious quantities, but it is the mental disintegration and corresponding physical decline of both cops that makes these films as difficult to watch as they are compelling.
Filth is based on the book of the same name by Irvine Welsh. It shares some of the features of that other Welsh novel turned into a film, Trainspotting (1996): the thick Scottish brogue, the use of music, the surrealism and music video-clip like portrayal of drug-fuelled psychotic episodes.
But whereas Trainspotting was groundbreaking and adrenaline-fuelled, Filth is dark (including darkly comic in parts) and infused with hopelessness.
McAvoy’s moments of clarity and glimpses of light just emphasise his character’s self-destruction, and how good an actor he is.
