All you need to make a film, according to Godard, is a girl and a gun: or, as it's been more succinctly put, kiss kiss bang bang. So it's odd how little attention most film-makers pay to the bangs, lazily reproducing whatever latest variation is in fashion – the rat-a-tat of tommy-guns in Thirties gangster movies, the pee-yowng of rifle ricochets in Fifties Westerns, the whoomph of pump-action shotguns in thrillers since the Eighties. One thing you have to concede to Michael Mann is that he really thinks about his guns: Hawkeye's longue carabine, with its almost lazy crash, in The Last of the Mohicans, the dry, tubercular rattle of the automatic rifles in the canyons of Los Angeles in Heat.
The most exciting moments in Public Enemies are the ones where Mann forgets about story and dialogue for a minute and just lets rip with the gats. In an early scene there's a telling contrast between the reckless spatter of Pretty Boy Floyd's tommy-gun against the business-like snap of FBI agent Melvin Purvis's rifle. Later on, there's a terrific night-time car-chase through the woods, Baby Face Nelson pursued by Purvis (Christian Bale) and a posse of G-men, the action reduced to the glare of headlamps and the flash of machine-guns, Bale's profile outlined in fire against the dark. At moments like that, you can almost lose yourself in the action and forget about some of the implausibilities in the surrounding story.
Public Enemies begins in the US of the early 1930s, when a combination of new technology and police jurisdictions that don't extend across state-lines are enabling bank robbers to get away with murder and large quantities of cash. John Dillinger (Johnny Depp) and his confrères have been living high on the hog, eating in swell restaurants, driving new cars, dressing like aristocrats and enjoying the sympathy of a public enraged by greedy bankers (can I smell a topical reference?).
J Edgar Hoover, director of the new FBI, declares a "war on crime" (there's that smell again) and drafts in the clean-cut, straight-shooting Purvis, famous and popular after killing Pretty Boy Floyd, to bring the bank robbers to justice. It's a great story, or would be if Mann could settle exactly which story he wants to tell and how he wants to tell it. Does he want authenticity, or does he want to wallow in old-fashioned gangster glamour? Does he want to tell the story of the noble G-men, or is he more interested in the dashing criminal? Or is he, heaven forfend, going to tell us again that rigid lawman and loose, flowing criminal are two sides of the same coin, just like De Niro and Pacino in Heat?
The screenplay is by Ronan Bennett, and there are some terrific one-liners: threatened with extradition to face trial in Indiana, Dillinger demurs – "I have absolutely nothing I want to do in Indiana." But otherwise, this is a Michael Mann film through and through.
To begin with, it looks as though authenticity is going to win out: the film opens inside a penitentiary, all black and white stripes and grey brutalist concrete; and outside there's nothing but flat, stale prairies. But pretty soon, glamour sets in – the glamour of period clothes and too-clean, too-new decor, and the glamour of mad love: kiss kiss. In a marble-lined restaurant Dillinger sets eyes on Billie Frechette (Marion Cotillard), and not long afterwards he's wooing her away from her job as a hat-check girl at an upscale club by hitting one of the customers in the face. Yeah, that always works with girls.
Depp plays Dillinger a good deal straighter than you might expect, no Jack Sparrow winks to the audience, but he is still a comparatively refined, dandyish kind of robber. The phrase "strictly from hunger" used to be an insult, but from hunger is how Dillinger ought to be, a desperate man, and Depp never suggests that. When Billie complains that he never thinks about tomorrow he ripostes that he's having too much fun today, but he doesn't look as if he's having much fun when he says it.
Meanwhile, Purvis and his G-men are pursuing Dillinger with the latest in scientific crime-fighting techniques. Mann has fun showing us some of their science at work, phone-taps carried out via a hilarious snakes'-nest of cables and a needle scratching into a spinning phonograph disc. But after a disastrous shoot-out with Baby Face Nelson (an enjoyable cameo by Stephen Graham), Purvis realises that his shiny youngsters are no match for the crooks' toughness and savvy; he needs to bring in some wily old law-enforcement hands, and the audience needs to forget that they've seen this plot-line in The Untouchables.
Little by little, interrupted by jailbreaks and hair's-breadth escapes, Dillinger feels Purvis's net closing in. He snatches Billie out from under the FBI's noses, but they snatch her right back when she stops at a tailor's to buy him his favourite brand of overcoat; and the Mob, who were his allies, decide that his brand of chaos is unhealthy. Law and order aren't always the same thing, and while the Mafia might not like the one, they do like the other. The story moves towards its fatalistic conclusion.
But fatalism, to have any impact, needs to be more single-minded and stately than this. All the way through, there's too much bustle, too many characters on both sides of the law to keep track of comfortably: Stephen Lang, playing an old-style lawman called Agent Winstead, hints at some genuine heft and nobility, but he's hardly on screen long enough to register. Dillinger's comrades, under their wide-brimmed hats, are almost interchangeable, so that their deaths feel perfunctory. You couldn't say that about De Niro's gang in Heat.
At the heart of all this is the problem that neither Depp nor Bale has the weight to fight the kind of duel Mann wants, and Bale is too stiff to hold the interest. Confusions of mood are exacerbated by some fussy camera-work – handheld jigging, switches between sepia and grainy, modern video. What it needs is the old-fashioned simplicities: a bit more black-and-white; a bit more bang bang.