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 one of the best shooters the CIA ever produced. He was also 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.
Twelve years is how long Doerr worked for the Agency the first time. Over a decade of helping to track down particularly nasty people who poses a threat to the country and then removing that threat permanently. He was very good at it though his bosses (one especially) found his habit of having a conscience an annoyance.
Then came the day he was told his teams of embedded 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. He worked as a copy editor for a major New York newspaper and though he sometimes did not like his job, at least it was normal.
Doerr is described as having a "six-feet four-inch, muscle-stuffed physique". He has been married for one year to his adored Gayle. He had been married once before, ended years ago when that wife died and he was left to raise their only child, Billy. It is when now 19-year-old Billy is murdered and no one knows who did it, Doerr decides his old talents were in need again.