The actress will play Lindsey, the notorious criminal's girlfriend and mother to his six-year-old son. The story, based the book Black Mass: The True Story Of An Unholy Alliance Between The FBI And The Irish Mob by Dick Lehr and Gerard O'Neil, follows Bulger (Johnny Depp) building his criminal empire in South Boston, with the help of longtime friend and FBI agent John Connolly (Joel Edgerton) and his brother (Guy Pearce) the former president of the Massachussets state senate.
For years, Bulger acted as an FBI informant to rid his neighborhood of other criminal elements. Connolly tipped Bulger off the the feds were planning to double-cross him, forcing him to go into hiding for several years, where he rose to the top of the FBI's Most Wanted List, before his arrest in Santa Monica, California in 2011. This real-life criminal served as the inspiration for Jack Nicholson's Frank Costello in 2006 Best Picture winner The Departed and Pete Postlethwaite's Fergus "Fergie" Colm in The Town.