Killing Xenu: A Scientology Murder Mystery

Psychological thriller by Rick Verde.
An international movie star is brutally murdered. Clearwater police department dispatches Detective Botti to investigate one of the biggest Scientology churches there. Clues lead him to an equally prominent musician. Detective Botti must find his missing daughter, and catch a serial killer whose obsession is to bring down the religious fiction that is Scientology.

https://www.amazon.com/Killing-Xenu-Scientology-Murder-Mystery-ebook/dp/B07GQW1SB4/

The Scientology Murders: A Dead Detective Novel (Dead Detective Mysteries)

A 2017 police procedural novel by William Heffernan, about the Church of Scientology.
Clearwater, Florida, is the spiritual center of Scientology. A senior church leader there employs a young man who will stop at nothing to make sure the church's rules are followed - including mass murder. The cops know who is doing the killings, but are powerless to catch the murderer because the Scientology hierarchy is protecting him.
The detectives are stonewalled at every turn. Harry Doyle gets pulled into the case when his adoptive father is shot while trying to rescue a young woman from Scientology. As the bodies pile up, the Clearwater police become more desperate. When the Scientologists move the killer to Alaska, Harry Doyle and his partner follow . . .

https://www.amazon.com/Scientology-Murders-Dead-Detective-Novel/dp/1617755362/