@thickurt@woof.group I haven't started it yet, but Michael Connelly (The Lincoln Lawyer, Harry Bosch) has an in-progress one "The Killer in the Code". It's about someone who claims to have decoded the Zodiac cryptograms, and says he's solved the Zodiac and Black Dahlia murders.

https://www.michaelconnelly.com/killer-in-the-code/