Tell me about working with Michael Mann…

Michael asked me about Purvis and I was delighted to do it. I’ve wanted to work with Michael for a long time and I was fascinated by the story he wanted to tell. He is one of the finest filmmakers, I think, and Public Enemies is one of the finest examples of filmmaking I’ve seen in years. His attention to detail, his ability to clarify a whole multitude of characters without it becoming confusing is just fantastic. The look of the picture, his ability to deal with the nuances of different characters, his appreciation for each and every person working with him, his obsession and energy is remarkable and he is so thorough.

There’s a fantastic scene, where Purvis and his men have trapped Dillinger in a farmhouse. How long did that take to film?

At Little Bohemia. We were up there for a good week or so. I don’t recall exactly the number of nights we were there but it was at least three nights of just solid gun battle. I must have fired thousands of rounds from the Thompson sub machine gun.

So what was it like working with Johnny Depp?

Fantastic. We had very few scenes — obviously the one we talked about. That’s the nature of it — clearly Purvis is pursuing him. And like Dillinger says in the movie, we have to be at every bank all the time and he can be at any bank any time, you know. Until the law was changed it was just an opportunity for men who had the stones to do it, to take full advantage of it. And also they could take full advantage of the public sentiment, because this was happening during the dust bowl era.

It’s interesting because you could draw some parallels with the anti-sentiment towards some banks now…

It’s become incredibly relevant. When Michael set out to make this movie who knew that this would occur? But in terms of the depression, the homelessness, the joblessness, the feeling that the fat cats, the bankers, had screwed people over resulted in somebody like Dillinger who never went after an individual’s money, he only ever went after banks’ money.

But these are the contradictions that make people fascinating…

Yes, absolutely. And that’s what I like about this movie. Nobody is wearing a black hat completely and nobody is wearing a white hat entirely.

Because Purvis is also ruthless…

Right. But he is cut from a different cloth. He is from a Southern patrician family, he is from the country, somebody who is used to hunting and we see that in the opening scene. And I like that scene between Dillinger and Purvis — although that scene is entirely fictional — where Dillinger actually appears to have some insight into where this will all end for Purvis, that this really is not for him regardless of how successful he is — and he is the most successful agent ever. I liked that very much and it makes him pause just for a second. You see Purvis pause and recognise that Dillinger has actually managed to peer inside of this man, certainly more than anybody else has.

What was your take on Purvis?

I found him to be a fascinating man. Clearly he is a supporting role here but I think that he is absolutely worthy of a movie completely devoted to him. He had an incredibly contentious relationship with J. Edgar Hoover, which began with Hoover very much as his mentor and Hoover regarded Purvis as his golden boy. Purvis was labelled the Clark Gable of the Bureau.

Is it true that his relationship with Hoover soured over the years?

Yes, I think that Hoover came to be jealous of Purvis over everything that he was originally charmed by. Purvis, at an incredibly young age —as was Hoover and as was Dillinger — rose to be the head of the most important office in the Bureau. To this day he holds the record of taking down the most public enemies. He fit perfectly Hoover’s ideal of what he wanted to transform the Bureau into — what he would call upstanding young men of a good background. He was a very capable man himself but it’s tricky with all of the technology and means that law enforcement has nowadays to be able to reflect and to see how outmanned and outgunned and outmanoeuvred law enforcement was at that time.

They were under resourced when they took on armed gangsters like Dillinger?

The FBI were not even given weapons until after the Kansas City massacre, they were not allowed to carry weapons up until that point. And you know it’s a brief period in American history where you not only had the Thompson sub-machine gun, the affordability of automobiles, you had loopholes in the law meaning they only had to cross the State line and they were scot-free and that meant that the gangsters had a huge advantage. Purvis was given a huge undertaking and the odds against him succeeding were huge.

In Public Enemies, Billy Crudup plays Hoover. He’s always been a fascinating subject and here we see him at the very beginning of his career…

Hoover was a visionary and the Bureau came to be incredibly successful but this was an era where we are witnessing the birthing pains of that organisation.

And is it true that Purvis ended his life by committing suicide?

Well, it’s never really been clarified exactly what happened. It seems most likely that he took his own life. There’s a possibility it was a mistake — there are some questions about a gun having been cleaned and having a round left in the chamber which he may have been unaware of but he had also been suffering from depression. Hoover had continued to haunt him and had caused him to lose a number of jobs and appointments that he was assigned to and to his dying day, Purvis had this tremendous respect for Hoover and could never understand why Hoover treated him the way he did.

So what was he like to play?

With my knowledge of him, I see a great deal more than maybe many people will be able to, in the movie. And especially what I think is the beginning of the end of the relationship between Hoover and Purvis. In the film he is essentially providing support in his role in actually taking down Dillinger. I do think it’s clear from seeing the movie that it’s a victory, a success, that Purvis considers to be too costly and one that has compromised his belief in the Bureau and has compromised his own values so much that it results in him quitting the Bureau within a year.