Public Enemies is a 2009 American biographical-crime film directed by Michael Mann and written by Mann, Ronan Bennett and Ann Biderman. It is an adaptation of Bryan Burrough's non-fiction book Public Enemies: America's Greatest Crime Wave and the Birth of the FBI, 1933–34. Set during the Great Depression, the film chronicles the final years of the notorious bank robber John Dillinger as he is pursued by FBI agent Melvin Purvis, and his relationship with Billie Frechette, as well as Purvis' pursuit of Dillinger associates and fellow criminals Homer Van Meter and Baby Face Nelson. Burrough originally intended to make a television miniseries about the Depression-era crime wave in the United States, but he decided to write a book on the subject instead. Mann developed the project and some scenes were filmed on location where certain events depicted in the film occurred, though the film is not entirely historically accurate.