A pulse of heat and fear rises from Kathryn Bigelow’s new film Detroit: a throb of desperate rage at black lives not mattering. It begins with a brief, deadpan animated history of African Americans’ internal emigration in the 20th-century United States and then comes to the Detroit riots of 1967, interweaving fictional scenes with news footage. The movie is dynamically shot by cinematographer Barry Ackroyd; like Bigelow’s previous pictures Zero Dark Thirty and The Hurt Locker, it is written by Mark Boal and like those movies it has a painfully fraught attitude to men in uniform.

The action runs from a heavy-handed police crackdown on an unlicensed drinking club that triggered the disorder to an incident the movie regards as the main event, which incarnates all the violence, racism and bad faith: the “Algiers Motel incident” in which three white police officers were accused, along with one black security guard, of murdering three black civilians and savagely beating many more, including two white women. Unlike the security guard, the three white cops signed confessions which were ruled inadmissible in court and all four were acquitted. Bigelow and Boal plausibly surmise that the security guard was caught in the wrong place at the wrong time. He became the victim of a stitch-up, and his well-meaning attempts at exemplary respectability earned him cynical contempt from the white authorities and laid him open to charges of Uncle Tom-ism from the black community.

As for the cop brutality itself, Bigelow suggests this was a case of incompetent and racist macho-sadistic mind games, like a Stanford prison experiment with live ammo. The movie has been accused of being deficient in nuance. But maybe so was the riot itself.

Detroit shows that the Algiers Motel outrage grew out of the fear and horror of the riot, with the authorities bringing in the army and the National Guard with tanks and deafening artillery, obsessed in that post-JFK and Vietnam age not merely with violence and looting but the possible existence of snipers, which made it not so much a matter of restoring order but a full-dress military counter-insurgency.

With authority and calm, John Boyega plays Dismukes, the black security guard entrusted with a uniform, rifle and sidearm. He is called upon to work an extra shift on the night of the riot itself, protecting a store, and makes an attempt to befriend the officials in uniform, offering cups of coffee. More level-headed than anyone else, he nonetheless finds himself drawn into a grotesque situation. The police respond to what they think is a shooter from the Algiers Motel: in fact, nothing more than a silly prank with a starting pistol at a motel-room party. Wired and paranoid, the racist cop Krauss (Will Poulter) decides this is the moment to teach the black people a lesson, along with his hateful comrades Flynn (Ben O’Toole) and Demens (Jack Reynor).

Facebook Twitter Pinterest ‘Wired and paranoid’ … Will Poulter, right, as racist cop Krauss. Photograph: Francois Duhamel/AP

But the heart of the movie is not in fact in the Algiers Motel: it is in the music of the Detroit soul group the Dramatics, whose early career is bound up with the tragedy of the riot. They are shown losing their early shot at fame: about to go on stage, the theatre is cleared by the police. And then, after the horrendous ordeal of the Algiers Motel, which is shown to affect band member Larry Reed (Algee Smith), the band are summoned in the early hours for an audition at the recording studio. It is an amazing scene, in that it appears to offer the Dramatics and perhaps even Detroit itself a miraculous kind of redemption. Larry is shown to be finding it difficult emotionally to carry on with showbusiness as usual – but should he, as a passionate gesture of survival? Or should he reject it all, as a mere crowd-pleasing charade? The story of the Dramatics bookends the violent events, and it brings a meaning and a sweetness to the film that it might not otherwise have had.

This is a sombre, grieving movie which appears to gesture to the ghost-town ruin that is still in Detroit’s future. It may not quite have the single compelling lead performance that some might have wanted from it, but it has relevance and passion, and by finding the story’s heart in the music of the Dramatics, Bigelow creates a humanity amid the anguish.

