Zellerbach is perhaps best known locally for his connection with two local high-profile cases. He successfully prosecuted William Lester Suff, who was convicted in 1995 of the brutal murders of 12 women and sentenced to death. Suff's victims were all prostitutes and drug users and many were either picked up or left for dead in the Lake Elsinore area. Largely because of his efforts on the Suff case, Zellerbach was chosen as the statewide Prosecutor of the Year in 1996. Swanson has been a Juvenile Court commissioner for three years.
Commissioners are county employees appointed by judges to fill judicial roles.
He has spent 23 years in both public and private practice, including 11 years with the Riverside County public defender's office and served two years as a police officer in Costa Mesa.