The Fly on the Wall — Tony Hillerman

John Cotton was a fly on the wall--the perfect reporter, seeing it all, hearing it all, but never being noticed. His best friend wasn't so lucky. He saw and heard too much and the last time John saw him, he was lying dead outside the Capitol. But death could not silence his reporter's notebook ...fragments of an awesome scandal. ..a senatorial candidate...millions in dirty dollars ... and the kind of cement nosy guys get buried in.

And when John picked up that notebook, he picked up the deadliest kind of enemies a reporter can have--people with something to hide.