April 1992. Los Angeles holds its breath as the trial of four white cops accused of beating black motorist Rodney King draws to a close. Meanwhile, on the street, detective Eldon Perry (Kurt Russell) is showing rookie partner Bobby Keough (Scott Speedman) the ropes: how to read a crime scene; how to plant evidence; how to finesse internal affairs; how to get away with murder. The funny thing is, he still thinks he's one of the good guys. Based on an original story by James Ellroy, and scripted by David Ayer (Training Day), this robust thriller effectively counterpoints history and histrionics, psychological drama and social melodrama. It's easy to forget that American genres exist alongside the real world, that cop movies might reflect real cops. The PC euphemism 'institutionalised racism' doesn't begin to describe the corruption and bigotry here located in the LAPD. Shrewdly, it is revealed not just in homicidal malfeasance but in camaraderie: a shared drink, a slapped back, the closing of ranks. Russell does his best work in years as the lifelong cop who comes to realise how steeped in cynicism he is. Admittedly, the mechanics of the mystery plot grate a little as Shelton contrives an implausible Western-style shoot-out, and the movie struggles to do justice to each of its four or five main players (they include Rhames and Gleeson on opposite sides of the career ladder), but mostly the cast wring truths from even the most familiar scenes. And the climax against the burning of LA is a tour de force, a maelstrom of anarchic destruction and insane anger that fuels a memorable, soul-searing mea culpa.