Joe Gores

An actual working detective and also spent a lot of time writing for television.

https://www.sfgate.com/entertainment/article/Joe-Gores-novel-about-Sam-Spade-s-early-days-3252173.php

http://therapsheet.blogspot.com/2011/01/gores-gifted-garrulous-and-generous.html

https://en.wikipedia.org/wiki/Joe_Gores