Warner Bros’ three-part documentary for BBC Two, directed by Michael Ogden, re-examines the case of serial killer Dennis Nilsen, convicted in 1983 for the murders of six young men. Crucially, the series shifts focus from the killer to the victims, asking why they remain just a footnote 40 years on and exploring how homophobic attitudes at the time allowed their disappearances to be overlooked. Police officers speak on camera for the first time about their regret over the premature closure of the investigation. The third in Ogden’s acclaimed “Files” trilogy, following The Shipman Files and The Yorkshire Ripper Files.