In 1946, the LAPD launched the Gangster Squad with eight men who met covertly on street corners and slept with Tommy guns under their beds. For two cops, Sgt. Jack O'Mara and Sgt. Jerry Wooters, all that mattered was nailing Mob boss Mickey Cohen. Their fates collided in the closing days of the 1950s and the aftermath would shake both L.A.'s mob and police department—and signal the end of a defining era in the city's history.

Award-winning journalist Paul Lieberman spent more than a decade tracking down and interviewing surviving members of the real police unit as well as families and associates of the mobsters they pursued. Gangster Squad is a tour de force narrative reminiscent of James Ellroy's classic L.A.Confidential.