Nick Broomfield’s documentary picks over the grisly bones of a serial-killer case that continues to haunt LA. In 2010, Lonnie Franklin Jr was charged with murdering 10 women over the previous quarter-century; he’d gained the nickname “Grim Sleeper” from the theory he had rested 14 years between killings, but Polaroids scattered around Franklin’s pad suggest other victims may simply have vanished into this impoverished, crack-scarred, deeply misogynist landscape. Broomfield’s follow-ups with friends and neighbours reveal how normalised Franklin’s behaviour had become – one thought nothing of the “motor oil” he cleaned from Franklin’s carpets – yet their oversight pales against the LAPD’s institutionalised indifference: you gulp on learning Franklin was apprehended only via an evidentiary fluke. Tough viewing, but the film-maker’s commitment is unmistakable: even after being pulled over for driving without a seatbelt – a trademark Broomfield bumble – he still thinks to ask the cop what he knew of this tragically compelling episode.