Max Doyle is an agent with the Phoenix Group.
That organization is an autonomous one though Doyle is told it operates "under the umbrella of Homeland Security". This very secret department which nobody had ever heard of, which is alright because "you're not supposed to", is nearly two decades old. "We rose from the ashes of 9/11".
The Phoenix Group was established due in large part to the Patriot Act under whose auspices the intelligence communities "went into overdrive with surveillance. Certain civil rights groups had a hissy fit. They didn't like them listening into phone calls or checking emails." In response to the protests, "the government needed to come up with a department that, if not exactly broke the law, then bent it a little." By bending, they mean that "we don't wait for warrants, we don't read Miranda Rights. We're the fast track when it comes to hunting down the bad guys. We find out something, then we take a back seat and let the other departments know. We point them in the right direction, as it were."
Our introduction to this man has him sitting in a prison cell in Fort Leavenworth. He has been doing so for the past three years of a life sentence, though likely to be considerable since he is there for murder. The first year had been spent, we are told immediately, in maximum security but after showing that 'he wasn't out to make trouble', he was moved to medium security.
However, his time sitting is extremely short, one paragraph, before he is put in a suit, handcuffed, and escorted out by two MP's. Doyle had thought he was flying to the funeral of his wife and six-year-old daughter. He was wrong.
Doyle had "served twelve years in the army, nine of those as an Army Ranger, before his arrest". He held the rank of sergeant (no idea which level) prior to being arrested for shooting his commanding officer in Afghanistan. This definitely makes Doyle sound like a deadly man and while that description is accurate, the charge of fragging his commander was not. The details of what happened on that day are fuzzy to him due to an explosion which rocked his world but when the dust cleared away, the senior officer was dead from a bullet from Doyle's gun and Doyle was sent away for life.
His time behind bars will be shortened when he is made an offer. The same person who actually killed his CO and left him to take the blame was the one who victimized his family and the Phoenix Group wants his help to catch that female assassin. What would happen after that was hardly of importance, of course, since he likely would not survive this first mission.