The movie is well-researched, based on the book by Bryan Burrough. It even bothers to try to discover Dillinger's speaking style. Depp looks a lot like him. Mann shot on location in the Crown Point jail, scene of the famous jailbreak with the fake gun. He shot in the Little Bohemia Lodge in the same room Dillinger used, and Depp is costumed in clothes to match those the bank robber left behind. Mann redressed Lincoln Avenue on either side of the Biograph Theater, and laid streetcar tracks; I live a few blocks away and walked over to marvel at the detail. I saw more than you will; unlike some directors, he doesn't indulge in beauty shots to show off the art direction. It's just there.