In January 2014, Cooper became attached to rewrite and direct Black Mass, a crime drama based the book of the same name by Dick Lehr and Gerard O'Neill, described as the "true story of Billy Bulger, Whitey Bulger, FBI agent John Connolly and the FBI's witness protection program that was created by J. Edgar Hoover." Barry Levinson had previously been involved with the project. Johnny Depp, who had been on and off the project for a number of years, came back on board to play the infamous Boston crime boss Whitey Bulger, alongside Joel Edgerton as Connolly and Benedict Cumberbatch as Billy Bulger. The film was released in 2015.