David Fincher The Big Nowhere (2009)

The plot is about three characters; L.A. Deputy Sheriff Danny Upshaw investigates a brutal sex murder which becomes a string of killings, working outside the law in his efforts to catch the killer. Turner "Buzz" Meeks, a disgraced former cop, now works for millionaire Howard Hughes and gangster Mickey Cohen as a fixer, and begins a dangerous affair with Cohen's mistress Audrey Anders. LAPD lieutenant Malcolm "Mal" Considine, involved in a bitter child custody case, tries, with varying success, to do the right things in an environment of deception, paranoia, and brutality. The three men gradually become part of a task force investigating Communism in Hollywood. The story takes place in the aftermath of the notorious Sleepy Lagoon murder case and the resultant Zoot Suit Riots.