I look for material that both interest me and challenges me. If I am drawn to the material and I have to work hard at it, the characters and the plots reflect the hours and hours of research.
As a lawyer, as a private citizen, you see a lot of injustice. You see a lot of people who should have been punished and are not, and people who were punished wrongfully are not vindicated. Fiction is sort of a way to set the record straight, and let people at least believe that justice can be achieved and the right outcomes can occur.
I'd read a lot of thrillers about politicians and presidents, but never one where you flip the stereotypes and make good people bad and bad people good.
The military is a very cool world to write about. I went down to Ft. Benning, Ga., for military training, and I learned a lot about soldiers and officers and why they joined up and what their life has been like.