Kind of Blue : An Ash Levine Thriller.

When a legendary ex-cop is mudered in L.A, the pressure's on to find the killer. Lt. Frank Duff needs his best detective on the case, but his best detective, Ash Levine, quit a year ago. A tenacious, obsessive detective, Ash resigned after Latisha Patton, the witness in a homicide case he was working, was murdered. Without his job, Ash is left unanchored -- and consumed with guilt that he somehow caused Latisha's murder. When he's asked to rejoin the force, Ash reluctantly agrees. Getting his badge back could give him the chance to find Latisha's killer. Ash dives headfirst into the shadowlands of Southern California to investigate the ex-cop's murder. But even when he has a suspect in custody, something about this case doesn't sit right with Ash, and he continues working the increasingly dangerous investigation while quietly chasing leads in Latisha's murder. Unable to let either case go, Ash finds that his obsessive nature might prove fatal.