"Black Mass should prompt a reevaluation of the uses and misuses of informers by law enforcement officials throughout the country."—New York Times Book Review
"[Shows] how fragile FBI integrity can be when the good guys lose sight of [the] truth, the rules, and the law."
—Washington Post Book World
"[A] jaw-dropping, true-life tale of how two thugs corrupted the FBI."
"Bone-chilling . . . one of the best nonfiction reads of the year . . . a powerhouse of a book. Dick Lehr and Gerard O'Neill . . . write like veteran novelists, weaving scene after jaw-dropping scene into a tapestry of sickening American corruption."
—New York Post