One would think a true writer would at least go on a ride along or interview cops in person if they're writing a book about a crime. It helps if the writer is an astute observer and actually CAN write. They'll glean enough information to write pages upon pages of descriptors which would lend much needed credibility to their writing. A good writer will then be able to describe situations to their readers which make them feel as if they're in the scene. I love a book where I completely forget I'm reading words as the scenes play out in my mind.
The rest just peruse the internet and cheat - then get upset when we don't leap at the grand opportunity to delve out police procedures.
Of every one hundred men, ten should not even be here. Eighty are nothing but targets. Nine are real fighters, and we are lucky to have them, for they make the battle. Ah, but the One... One of them is a Warrior... He will bring the others back.
"Wrong door, buddy!"
Let no man's ghost say my training failed him.