This is the 3rd book in the Sonny Haynes series.
1953: When a young actress is sexually assaulted on the set of a Western film in Twentynine Palms, California, fixer and ex-LAPD homicide roach Sonny Haynes is brought in to manage the spiraling situation. Add in a Palm Springs mob boss, a pair of bodies at the Starlite Hotel & Resort, and a mysterious connection to snuff films, and Sonny has his hands full in Under a Black Flag, the culmination of which leads to the heart of darkness itself in the Southern California desert.