J.T. Ryan is a private investigator.
He is a very active one from all accounts keeping quite busy and making a better than decent living from it. He also is willing to drop everything to lend a hand to the FBI, especially on matters dealing with terrorism.
The person he is most closely associated with at the Bureau is Erin Welch, Assistant Director in Charge of the FBI's office in Atlanta, with whom he has worked on numerous cases. She makes no bones about the fact that she likes calling him in when cases get particularly messy because he was "someone who can cut through the bullshit, the procedures, and get their hands dirty". In addition as he put it, "maybe break a law, now and then, to get the job done", to which she did not argue.
As a former Army Special Forces officer for a few years, Ryan has a good deal of experience in getting the job done as well occasionally getting his hands dirty. When the dirty parts come along, he has his Smith & Weston .40 cal pistol on his nightstand or in his holster to help even the odds. The comments concerning getting his hands dirty and to play by his own rules are demonstrated in one adventure when he captures a man the FBI had been wanting, calls Welch to report it, and the first question she asks is "Is he alive?"
Ryan is described as having close-cropped brown hair and a rugged appearance. For most of the adventures we have of him, he has a steady girlfriend named Lauren so while his eyes do a considerable amount of wandering, for the most part he stays a good boy.
In addition to working with and for Welch, Ryan has several occasions to work with a CIA agent named , a woman very much liked by Ryan because she is not only like him in attitude and aptitude, on their first meeting she saved his life. That kind of thing stays with a guy.