Non-fiction books on the history behind the L.A. Quartet?

I’m re-reading Big Nowhere after 25+ years, and hankering to know more about the real history Ellroy weaves in. I figure books on the Black Dahlia case are pretty easy to find. But any suggestions for layperson-accessible but historically responsible, non-sensationalist books on the intersections of crime, policing, politics, and race in post-WWII L.A.?

Thanks!