Public Enemies is the story of John Dillinger, the silver-tongued bank robber turned folk hero of post-Depression America, and it’s another riveting slice of American crime cinema from director Michael Mann (Heat, Collateral). The film opens with a terrifically visceral jailbreak sequence, as Dillinger busts his gang out of the Indiana State Penitentiary, and the narrative then traces the frenetic 15 months that followed, as Dillinger robbed banks, murdered cops, became a household name, and died on the sidewalk outside the Biograph movie theatre. Mann and star Johnny Depp, who plays Dillinger, spoke about the project at the film’s London press conference:

MANN: “What really interested me was not so much that he [Dillinger] gets out of prison but he explodes onto the landscape, and he’s determined to have everything right now. He lived the dynamic of maybe four or five lifetimes in one, and that one life is only 15 months long, and it has the intensity of white hot brilliance to it.

He had no concept of future. He planned bank robberies with great precision but they didn’t plan next Thursday. There was no sense of, as with Butch Cassidy and the Sundance Kid and the Hole In The Wall gang, ‘maybe I can make a quarter of a million dollars and go to Brazil for a year and a half and chill out’. There was no endgame. There was this very very intense ‘live for today and whatever happens tomorrow is fated’.”

And what drew Mann to the smirking, charming, cop-murdering media darling that was John Dillinger?

MANN: “First of all he was very bright and he was great at doing what he did, he’s regarded as one of the greatest bank robbers in American history, whatever that’s worth, but he was very current and contemporary within his time, he was very sophisticated, and he planned his robberies with great precision and forethought. They employed techniques picked up from the military, and Herbert K Lam where the expression ‘on the Lam’ came from. Dillinger’s time in prison was really a postgraduate course in robbing banks.”

And how did Leading Man Number One come to identify with Public Enemy Number One?

DEPP: “What made it for me was when I made the connection that John Dillinger was born in Indiana, and raised… about two hours from where I was born and raised. It was at that point that I thought, ah, I hear his voice now, I know him, I know what he sounds like. He’s my grandfather, who drove a bus in the day and ran moonshine at night, he’s my stepfather who did time at the state penitentiary.

To be able to fire my Thompson out the same window, the very window that John Dillinger fired his during the gun battle… you can’t put a price on that… to walk the walk outside the Biograph Theatre and land exactly to the millimetre where John Dillinger’s head fell, outside the Biograph… was magical.”

It may be difficult now for us to remember a time when Depp was anything but one of the most bankable men in Hollywood, and universally accepted as one of the greatest actors of his generation to boot. He reminded us that a little series of artistically questionable pirate movies based on a theme park ride have made a great contribution to his current clout:

DEPP: “I went through twenty years of basically what the industry described as failure. For twenty years I was defined as box office poison. And I didn’t change anything in terms of my process, I didn’t change a thing, and then that little film Pirates Of The Caribbean came out, and I thought ‘yeah, that’d be fun, to play a pirate, for my kids’ and all that stuff. So I created the character in the same way I’ve created all the other characters. And nearly got fired. And thank God they didn’t [fire him], because it changed my life. So I’m hyper, super thankful that that radical change happened. But it’s not like I went out of my way to make it happen.”

So there you go. The Pirates Of The Caribbean franchise may represent the death of narrative cinema, but it has its use. Depp found time to pour praise on British actor and star of This Is England, Stephen Graham, who plays Baby Face Nelson in the film:

DEPP: “I think he’s magnificent, Stephen Graham – he’s one of my favourite actors of all time. What he did in This Is England absolutely destroyed me, what he did and what Combo [Graham’s character] did in that film, and Shane Meadows [the director], took me to my knees. Stephen Graham is someone I’m gonna fight to get, I’m gonna force him to be in all my movies.”

Graham’s rise really has been quite astonishing – from a crappy part in Snatch, the second instalment in Guy Ritchie’s Geezers Are Great ouevre, to a show-stopping performance in This Is England, and now a terrific display in this Michael Mann blockbuster as the psychotic Nelson. Quite the career trajectory. Although I wonder if Depp will be able to squeeze him into Alice In Wonderland. Cheshire Cat anyone?

But here’s what all true movie fans were waiting to hear – Mr Depp’s advice on how best to maintain your looks:

DEPP: “Clean living. I think if you can avoid wine, I’d do it. And liquor definitely. Avoid liquor. Most definitely don’t smoke. Anything – don’t smoke anything. Yeah, stay in your room. Watch a bit of reality television. That’s how I do it.”

On reflection, he may have been kidding.

And finally – John Dillinger was shot down as he left a screening of Manhattan Melodrama, staring Clark Gable. If he could choose, what film would Depp watch before he snuffed it?

DEPP: “Withnail & I. Without question.”

Damn straight. Still, I’ll be looking forward to the Johnny Depp & Shane Meadows collaboration…