Shawn is the creator and executive producer of The Shield and The Chicago Code. He is a native of Rockford, Illinois. He attended Middlebury College, where he earned a joint degree in Theater and Economics and began writing plays for the first time.
After moving to Hollywood, He became a staff writer for the show My Two Dads. He later became a writer for the shows Life with Louie and Nash Bridges. He was also producer/writer for Angel. During that time he also wrote a couple of screen plays including Welcome to Hollywood and a short film entitled The Good Things.