Todd Boling is a Congressional aide.
He is no spy. No covert operative. None one trained in such matters. No desire to be one. In fact, he is very much in the "haven't decided what" mood when we first meet him and is doing something different just to be different and to take a breather before deciding anythink about his future. Some breather he finds.
He is a young man, likely 18 or 19, who was still applying to colleges, trying to decide where he would go if accepted and what he would study. In the meantime he was lucky enough, if such a word applies considering what was in store for him, to get an internship to stay and work the summer for his local Congressman. He figured it would be fun, interesting, something different, and a nice bullet point on his resume. [The bullet-point is my addition but in view of the number that start flying his way, it is more than apt.]
Boling hails from Houston where in high school he had been a long distance runner for his school's varsity track team. This shows he is in very good shape and used to strenuous exercise requiring considerable stamina. That quality will also prove extremely important in staying alive considering the number of people very earnestly seeking to find and eliminate him for having been in the wrong place at the wrong time and seeing the very wrong thing he saw.
In the first two adventures, it is definitely a case of someone having to react to very bad people doing very bad things and intending to do even badder things in the future. I guess he just got tired of defense and, when offered later on in the series a chance to go on the offensive, he readily agrees.