Who is Dwight Shales from 'F' Is for Fugitive: A Kinsey Millhone Mystery and what is their importance?

Dwight Shales is the principal at the high school. Over the course of the novel, we learn that Dwight had a relationship with Jean. Ann, however, was in love with Dwight and believed that the baby Jean was carrying belonged to him. She then killed Jean in order to protect Dwight from the scandal Jean's pregnancy would cause.