Black Mass: The True Story of an Unholy Alliance Between the FBI and the Irish Mob by Dick Lehr and Gerard O'Neill
Between the 1970's and 1990's, the Boston crime world was impacted and largely run by one man from South Boston: James "Whitey" Bulger. What most of his associates didn't know was that Whitey Bulger was also an informant for the FBI. In Black Mass, two staff writers from the Boston Globe take on the difficult task of drawing together testimony and the FBI's secret files (as well as reading between the lines) in order to show how the FBI colluded with one of the most notorious gangsters in Boston. It's chilling to read as the facts pile up and serve to strengthen the argument that Whitey Bulger was the one controlling his relationship as an informant--getting away with murder, extortion, and drug running while drawing down threats presented to his own gang from La Cosa Nostra in New England. I'd suggest complementing the book by watching Martin Scorsese's take on the tale in his award-winning movie The Departed.