John Mattingly is a former sergeant with the Louisville Metro Police Department in Kentucky. He was involved in the very high profile case involving the death of Breonna Taylor that occurred during the service of a valid search warrant on her residence.  John survived a gun shot wound during that incident and has since published a book titled, 12 Hours in the Dark. You can purchase his book at the link below.

https://www.amazon.com/12-Seconds-Dark-Officers-Firsthand/dp/1956007016

Don't forget to also purchase your copy of my own book, Never Off Duty. 

https://www.diangelopublications.com/books/never-off-duty