L.A. '56 by Joel Engel is subtitled: A Devil in the City of Los Angeles. It is a true crime story written more in the mode of fiction. The conversations are actually "recreated" or in my words: fabricated. They are based on facts, interviews, testimony and so on.
The devil is serial rapist, Willie Roscoe Fields. The hero is Detective Danny Galindo. Engel shows how Los Angeles was in 1956 via inclusion of movies showing, songs playing on radios, or at juke joints, what television shows people are watching and mentions of print or voiced ads, among other tidbits. Engel also includes copies of actual news articles from the year.
The statement: "An article that appeared in the California Eagle but was not in any white newspapers--not the Los Angeles Times, the Herald Express, the Examiner, the Mirror--the summer of 1956." appears at the bottom of each news article shared.
Galindo gets along with other law enforcement personnel because he makes it his business to get along. Many who work for the LAPD are racists and bigots. Danny thinks he escapes the torments suffered by Negro officers because his co-workers forget he is Mexican/American or are not as full of hate for Mexicans as they are of black skinned people.
Thus the crime novel is also a history of segregation lesson, specifically how it applies to Los Angeles and the LAPD.