Max Bowman is a private investigator.
He put in his time, as they say, with the Agency. A long time, according to him, starting back when Reagan was the President, which is not how he put it but his way was a bit coarser which is pretty much the way the Bowman puts most things. Bowman does not worry about political correctness or delicate ears or polite conversation.
Anyways, back to his history, he worked in the CIA for quite a while "so I established myself well enough. After I went freelance, I kept getting a steady stream of customers. Most of it was s**t work. Usually, the Agency had lost track of an ex-agent and a higher-up for some reason got in a sweat about what had happened to him. Did he defect to China? Worse yet, was he writing a tell-all that might make that higher-up look like a moron, which was probably about as difficult as breathing? They didn't have the time or the resources to go after all these lost sheep, so they hired me to do it, because I knew them and they knew me. And by the time I found the guy, they usually forgot they were looking for him".
Bowman's work with the Agency came from his father having worked there, having been with the OSS during WWII and switching over when it turned into the CIA. Bowman was "raised to be an Agency man". Note: at first I was not sure if that is true because it was something he told someone and sometimes what Bowman tells someone is not really the truth. Not that he is a habitual liar as such but sometimes a good less-than-true story can get better results than the straight facts, again according to Bowman. Anyways, Bowman lets us know later that it was the truth with his father grooming Bowman and his two older brothers to join - the other two bolted but Bowman signed up. This was before, as he tells it, those in the Agency, including himself, "grew over-the-top paranoid, primed to destroy a threat even when there wasn't one".
Not all the cases that Bowman works on come to him from the CIA but it seems that one way or another, no matter who brought the assignment to Bowman or why, the CIA will be in the details somewhere. Of course, that could just be more 'over-the-top paranoia'.