Levi Hart is an agent with Dragon Team.
That "group" was a close-knit team of eight highly trained operatives, put together as just one of a dozen such teams all working for Vanguard International. Vanguard was a company created by Heath Baker, a decorated colonel with the Green Berets who paid his dues with multiple tours in Vietnam and has the medals and the scars to prove it. After 9/11, he formed the company as a side venture to help do his part. These teams "at first ... performed surveillance, personal protection, and a variety of other tasks for private clients but the Iraq and Afghanistan efforts [soon] provided the principla contracts".
Dragon Team was led by a former Seal name Joe Tucker who brought in Levi Hart as his assistant and for the past few years, the that team has more than proved its worth in a good number of very bad assignments. Tucker and Hart were two men drastically different from each other who very much disliked each other at the beginning but whose opinions changed in the heat of battle so that now they are bests of friends.
Levi Hart is a former FBI agent who was making a name for himself and had even reached the position of Assistant Special Agent in Charge after just 5 years on the job before things changed and he decided a change of career was in order. Now he earns a lot more and gets a lot more action that before and enjoys it a whole lot more. There are rules to what he does but nothing like the ones as a Fed.
Hart is described as having "heavy auburn hair brushed straight back" with "slender and angular, with a lean face, a shy grin and knowing eyes. He was thirty-seven but passed for ten years younger".