 Joining the Los Angeles County Sheriff's Department as a deputy, he was a Superior Court bailiff from 1961 to 1969.After obtaining a law degree in 1969 from the Whittier Law School and passing the California State Bar Examination in 1969, Dorn worked as an assistant city attorney for the City of Los Angeles until 1979.California Governor Jerry Brown appointed him to the Municipal Court in 1979 and to the Los Angeles County Superior Court in 1980.