The Devil's Double, Lee Tamahori, 108 mins (18)Elite Squad: The Enemy Within, José Padilha, 115 mins (18)The Interrupters, Steve James, 125 mins, (15)

Operation Desert Pants has run out of gas? Thank goodness for double agent Dominic

I t takes a special kind of monster to be deemed a dangerous liability by Saddam Hussein, but Uday Hussein was just such a loon. He was Saddam's eldest son, as well as a homicidal maniac and serial rapist.

But he was sane enough to employ lookalikes to take his place in public whenever an assassination attempt seemed likely – that is, most of the time. The Devil's Double is based on the life story of one such lookalike, Latif Yahia. At the start of the film, in 1987, he's a lieutenant in the Iraqi army, but after Uday makes him an offer he can't refuse, he's thrown into a playboy world of champagne, cocaine and gold-plated guns.

It's a fantastically fertile premise for a gangster movie, and it's the showcase of a lifetime for Dominic Cooper, who plays both the lead roles. Often acting opposite himself, he's skilful enough that you can always tell immediately which of the two men you're watching – the quiet, wary Latif or the giggling, strutting Uday. You even fear for Latif's safety, forgetting for a moment that the person threatening him is played by the very same actor.

It's a pity that the film around him isn't quite so impressive. It could just have stuck to the nauseating facts of Uday's life, or it could have used them as the foundations of a fictional thriller, but Michael Thomas's script falls between these two stools. For most of its running time, The Devil's Double is a fascinating but superficial magazine article about Uday's excesses, but later it bolts on some hackneyed B-movie complications which are so absurd that they make you doubt the truth of everything that's gone before. It's still a watchable film, but Latif – and Cooper – deserved better.

Elite Squad, released in the UK in 2008, was a huge hit at home in Brazil, and rightly so. Not only was it a thorough dissection of corruption and gang culture in Rio de Janeiro, it also had characters you cared about and some of the most nerve-jangling action sequences in recent cinema. These sequences, however, led to criticisms that Elite Squad was an apology for police brutality: its paramilitary heavy mob, the Skulls, tackled the crime in Rio's favelas by torturing and shooting anyone who got between them and a drug dealer.

One of the intriguing things about the sequel, Elite Squad: The Enemy Within, is that it addresses those criticisms. It introduces a human rights activist who condemns the Skulls, and it relegates the first film's take-no-prisoners hero, Wagner Moura, to an office job where he discovers that the city's governors make the drug barons he's used to seem like choirboys. It's a rare sequel that honours and expands on its predecessor. However, by shifting the focus from Rio's mean streets to its corridors of power, The Enemy Within loses the juddering impact that made Elite Squad so exhilarating.

There's more inner-city unrest – an issue which confronted us all last week – in The Interrupters, a documentary by Steve James, the director of Hoop Dreams (1994). His subject is CeaseFire, an organisation of "violence interrupters" who intervene whenever they hear of a fight breaking out in Chicago's poorest neighbourhoods. The interrupters try to pacify people on a case-by-case basis, rather than rooting out the cause of the trouble, and the documentary, too, concentrates on a few individuals rather than asking why whole sections of America's cities have become war zones. It feels like a cop-out compared with the more political Hoop Dreams, but The Interrupters is still a deeply moving documentary. The men and women it profiles are more heroic, and for the most part more charismatic, than any of the make-believe heroes you'll see at the cinema this year.

Next Week:

Nicholas Barber sees Daniel Craig and Harrison Ford in Cowboys & Aliens

Also Showing: 14/08/2011

The Smurfs (103 mins, U)

Belgium's blue gnomes are magically transported to New York, where they teach Neil Patrick Harris the supposedly important life lesson that it's wrong to want a bigger apartment. File it below Mr Popper's Penguins, but above Zookeeper, with which it shares a man-pees-in-the-middle-of-a-posh-restaurant scene.

Beautiful Lies (115 mins, 12A)

Audrey Tautou plays an Amélie-ish hairdresser – she's even called Emilie – who passes on an anonymous love letter to her lonely mother. It's an overlong but well-assembled romantic comedy, à la the 1940s James Stewart romcom, The Shop Around the Corner.

The Salt of Life (98 mins, 12A)

Rome's Woody Allen, Gianni Di Gregorio (Mid-August Lunch) writes, directs and stars in this rueful comedy about a put-upon retiree who tries and fails to chat up younger women.

The Taqwacores (83 mins, 15)

Grungy American indie drama about Muslim punk rockers.

Film Choice

J J Abrams out-Spielbergs Spielberg with Super 8, a nostalgic tale of teenage film-makers who meet a creature from outer space in small-town 1970s America. In Arrietty, Studio Ghibli's adaptation of Mary Norton's The Borrowers, each of the miniature people have more charm than all 100 of the Smurfs combined.