According to THR, Sherlock star Benedict Cumberbatch and Parks and Rec star Adam Scott have been cast to star alongside Johnny Depp in Black Mass.
Black Mass is based on the book Black Mass: Whitey Bulger, The FBI, And A Devil's Deal. It follows the life of Whitey Bulger. Whitey is famous for being a head mafia boss, who up until recently was on the run from the FBI. The story will follow Whitey's life from starting out as a low level street thug in south Boston* through his rise to the top of organized crime.
Cumberbatch is going to be playing Whitey’s straight laced brother Bill Bulger. The role was originally going to be played by Guy Pearce. There is no word on why the change was made, but they didn’t downgrade with the switch. Scott will be playing FBI agent Robert Fitzpatrick.
The movie will also star Joel Edgerton, Dakota Johnson, Jesse Plemons, and Juno Temple. It will be released in October 2015.
*Correction: A previous version of this article said that Whitey Bulger grew up in Ireland, not Boston.