Who is Carl Perkins from Sweet and Deadly and what is their importance?

Carl Perkins is Catherine's neighbor and friend. When he moved to Lowfield from Louisiana he was a poor man. Over time, he made himself rich through business. Carl is proud of his success and shows it off with the huge mansion he built down the street from the Linton home. He is also an important member of the community, holding many political positions in the city, including coroner. It is Carl Perkins who runs the coroner's jury when Catherine finds Leona's body.

In the end, we learn that Carl has leprosy, and that it was Carl who killed Catherine's parents, as well as Leona to keep his condition a secret.