With Johnny Depp in a cool black hat and thrilling tommy-gun shootouts, does Public Enemies set up a shrine to movie gangsters? Maybe so, admits director Michael Mann. By Will Lawrence

ALONG with the cowboy, the gangster has evolved into an icon of American cinema. For decades, countless B-movies have cast the Depression-era mavericks as near-mythological creatures, their exalted reputations often far removed from the seedy reality. Consider Bonnie and Clyde, the anti-heroes of arguably the most famous of all gangster flicks: in Arthur Penn's 1967 classic, Warren Beatty and Faye Dunaway expire in a hail of bullets, the 187 rounds pumped into their Ford V8 sedan turning it into something akin to a block of Emmenthal. The history books confirm their violent demise, but their real-life adventures were markedly different from the Hollywood fantasy. These were small-time crooks; both were crippled and neither was an effective bank robber. Their deaths and the media reaction, however, crystallised their fame.

Much of their story is charted in Bryan Burrough's history of the 1930s crime wave, Public Enemies; and it is to this book that Heat, Collateral and Miami Vice director Michael Mann turns for his entry into the rat-a-tat realm of Depression-era blood and bullets. Mann, however, is concerned with just one of these shady characters: John Dillinger (played in the movie by Johnny Depp). During the early 1930s, this wisecracking Indiana farm-boy pulled off a string of high-profile heists (clinically executed by Mann on screen, who zips in and out as quickly as his subject), demonstrating such professionalism and skill that his exploits - he hit dozens of banks between the summers of 1933-1934, taking an estimated $300,000 - prompted a four-month manhunt. The nascent FBI, under the stewardship of J Edgar Hoover (Billy Crudup), dispatched agent Melvin Purvis (Christian Bale) to bring back his body.

"What I liked about Dillinger was that here was the greatest bank robber in American history," begins Mann, "and yet he definitely won the heart of the nation, becoming an outlaw-hero." During two early incarcerations - Dillinger escaped from jail in both Crown Point and Lima - real-life reporters accustomed to cold-eyed Chicago gangsters had found this light-hearted criminal bright and charming. As Mann demonstrates, Dillinger knew how to play the press. Their gushing copy helped cast him as a sympathetic crook, one whom audiences could cheer as his tale became a national soap opera. The stock market had crashed and the country was mired in depression. The populace blamed the banks. And here was Dillinger, the charismatic rebel, embodying the desires of the nation and piddling in the fat cats' cream. It's also said that he most likely killed only one man.

"John Dillinger didn't appear as a bad criminal; he went out there and he was a star," smiles Johnny Depp. "He spoke to the people and they absolutely loved him. He was a hero. This was all unfolding at the height of the Depression and so many people had had their lives ruined, when they saw someone fighting back against the banks, they loved him for it." The history books attest to the fact: more than 5000 people turned up to see his internment. "And, importantly," continues Depp, "I think that by this stage of his life, Dillinger had found himself - he was at peace with the fact that it wasn't going to be a very long ride, probably, but it was going to be a significant one."

Depp's performance in the film oozes charm and charisma, all the while suggesting that something darker lies just beneath his character's wiseacre veneer. So often cast as one of cinema's waifs or strays, here Depp embraces Mann's desire for a complex antihero. Shorn of the usual cartoon-like characteristics of the snarling gangster, he summons an enigmatic turn, as he and Mann bid to answer a beguiling question: why would such an accomplished criminal choose such a wilfully short ride? Why would he operate with no back-up plan, no escape route, no way out? Clearly, Dillinger wasn't stupid. Maybe he believed he was invincible, a better man than Purvis and those that chased him down? Mann clearly thinks so. "They ain't tough enough, smart enough or fast enough," coos Depp's Dillinger midway through the movie.

"Dillinger had this love for life," continues Mann. "He was a smart and charismatic and impassioned man, and he outran, outfought and outsmarted law enforcement across the country. To me, his life seemed to be a compression into 13 months of two or three lifetimes. The engine inside of all that was that he had an intoxication with life that had been denied him during the nine years or so that he'd spent in prison. And he was going to have everything, right here, right now." The film's coolest moment sees Dillinger courting Billie Frechette (played by Oscar-winner Marion Cotillard) with the line: "I like baseball, movies, good clothes, fast cars ... and you. What else do you need to know?"

Mann smiles. "If you think about it, Dillinger was almost obsolete, an anachronism, but he was so very, very good at what he did that he managed to prosper, to succeed in spite of everything that was ranged against him. What I hope we show in the film is that there are two evolutionary forces at work, both of which are working against him. First, there's organised crime, which was moving into a corporate, capitalist world and it doesn't want Dillinger and other outlaws causing trouble, carrying stolen money across state lines. And also there's Hoover and what he was doing with the FBI, creating a focused force to go after these types of criminals."

Christian Bale, who leads the FBI's on-screen manhunt, agrees, claiming the outlaws' adventures were "like the last dying breath of the Wild West". It might sound romantic, but it is, in fact, a valid point. As a robber of banks, Dillinger was one of the final practitioners of a dying craft, an heir to Jesse James and Billy the Kid, a man who saw the sun finally set on a fading notion of a Wild West, where men could ride into town, bust into the bank's safe and scuttle away, smuggling their booty over state lines.

Indeed, the world the 66-year-old director re-creates for Dillinger recalls that lawless age; the film projects a near-sepia 1930s, hinting at a more lawless history, the muted palette reflecting directly the gloomy atmosphere of the times. And by shooting with super-high resolution digital photography, Mann immerses the audience in this brooding gangsters' realm, carrying us up close and personal. The film's main set piece, a machine-gun shootout at Little Bohemia Lodge, in which Dillinger and Baby Face Nelson exchange a symphony of gunfire with the Feds, is a case in point. You can almost feel the bullets zinging past your ears. Fans of the LA street battle that opens Mann's feted 1995 De Niro-Pacino piece, Heat, will not be disappointed.

"Of course you want people to enjoy the action scenes," says Mann, "but that's not the purpose of the movie. You also want audiences to appreciate that this is a love story." Like Mann's first big-hitting feature, 1992's The Last Of The Mohicans, the love story helps drive the narrative. "You see all this passion with Dillinger and he focuses that on Billy Frechette." As the movie hurtles towards its climax, Frechette can see that her lover's days of misadventure are numbered. She pleads with him not to return to Chicago, but he does, arriving in a town ablaze with his own notoriety. "On the night of his death, he went to the cinema to see Manhattan Melodrama, the Clark Gable movie, and it contains this line: Die like you live - all of a sudden.' I think Dillinger would have liked that."

Unlike so many of his peers, including Bonnie and Clyde, Dillinger's actions underscored his legend. As the film bids to portray, he was imbued with his own mythic qualities, and that's why he deserves his place at the forefront of America's gangster saga. The FBI closed the book on this passage of history, but his tale remains a fitting final chapter. Mann's Public Enemies, meanwhile, stands as an expertly forged epitaph.

Public Enemy goes on general release on Wednesday.