Max Doerr is an agent with the CIA.
Technically, he was. Then he was an editor for a New York City newspaper. Then he was an agent again.
That is what we learn early on in this series where Doerr was fresh out of college hired by the Agency. He went through through the standard period of training before being sent into the field as a rookie. He showed right away how good he was at his craft and how deadly he was as a sniper, dispatching more than a couple of people deemed worthy of extreme prejudice. He was very effective in putting together intelligence teams, running them successfully throughout the Middle East, but it was as a sniper where his reputation really grew.
Then he was told his teams of imbedded spies and informants were not longer needed - not cost effective. Drones and intercepts could do all that. Close down operations and let his people dangle. He refused. He was ordered. He baulked. Then he quit. Found a new job and a new wife and started again.
When his teenage son from a previous marriage is murdered and no one knows who did it, Doerr decides his old talents were in need again.