The Flower in the Sand by Gregg E. Bernstein

It's 1956, and LA is hot as an oven and smoggy as hell. Private investigator Cole Dunbar grew up on old Bunker Hill and rode Angels Flight to school, but angels have no place in this city anymore, where strippers and burned-out cops take their secrets to the grave. He already has a head full of nightmares from World War II, but after he receives a mysterious phone call from a rich client, her case, and her beauty, drag him into a witches' brew of arson, missing people, and murder. He's already seeing a therapist to help him fight his way back to normality, but after he takes a fateful trip to Mexico and is framed for murder by the LAPD, it's going to take a lot more than therapy for him to come out of it alive and finally pin the tail on the right donkey. Evidence stolen from a police locker, cutting-edge science and advice from LA's biggest con man help, but will it be enough to stop the man who's murdering his way to a fortune in blackmail money?