Errol Morris and Werner Herzog never did open the grave of Ed Gein’s mother in 1975 to establish whether the serial killer had exhumed her corpse: Morris had second thoughts and stood Herzog up at the graveside. Nor did Morris make his planned debut film about the form of insurance fraud popular in Vernon, Florida, whereby residents lopped their limbs off to claim compensation: death threats from the “nubbies” put him off, and instead he made a gentler tribute to the town’s stash of eccentrics (1981’s Vernon, Florida). Morris did, however, succeed in getting Werner Herzog to eat his shoe, an event immortalised by Les Blank in the short documentary Werner Herzog Eats His Shoe. The gesture was in settlement of a bet Herzog had made that Morris would never complete his first film, 1978’s Gates of Heaven, a study of the owners of pet cemeteries which Roger Ebert rates as one of the ten best films ever made.

The first two films – and the anecdotes around them – now form the bedrock of a career that has seen Morris acclaimed as the father of cinematic documentary. His 1988 film The Thin Blue Line covered a miscarriage of justice, and helped to get its subject out of jail as well as establishing Morris’ status as a filmmaker. The fact that it was not nominated for an Oscar® raised widespread questions about the Academy’s processes. Morris would get his Oscar® in 2004 for his documentary on the Vietnam-era Secretary for Defence, The Fog of War: Eleven Lessons from the life of Robert S Macnamara. Key to Morris’ interview technique is the “Interrotron”, which he first used on Fast, Cheap and Out of Control in 1997. This machine permits the interviewee to speak directly to Morris whilst looking into the camera; “there is,” as Morris puts it, “no third party”. The Interrotron comes into its own once again in his latest film Standard Operating Procedure, which features extraordinarily frank long-form interviews with the soldiers convicted of prisoner abuse at Abu Ghraib.