He earned a Juris Doctor degree from the Villanova University School of Law and was admitted to the Delaware Bar in 1983.
[3] Seitz served as managing partner of Connolly Bove Lodge & Hutz LLP, where he practiced for more than three decades.
[3] On February 23, 2015, Governor Jack Markell nominated Seitz to be a justice of the Delaware Supreme Court to the seat vacated by Henry du Pont Ridgely who retired on January 31, 2015.
On October 24, 2019, Governor John Carney announced Seitz as his nominee to be the next Chief Justice of the Delaware Supreme Court.
His father is Collins J. Seitz, who served as a Judge on the United States Court of Appeals for the Third Circuit until his death in 1998.