Who is Doug Carmichael from Blood Test and what is their importance?

Doug Carmichael is the son of a senator, he is wealthy but works for a company that specializes in fantasy role play with a sexual slant. He has known Nona Swopes since they were teenagers and has found a way to spend time with her continually over the years. Doug fears his father and reveals that he was abused as a child. He is about to kill Alex when the sheriff intervenes. When Doug persists, he's shot and killed.