Born in Syracuse, New York, Richman graduated from Birmingham High School in 1971 and earned his Bachelor of Science in 1975 from the University of California, Davis, where he played baseball and was named an All-Conference pitcher.
After graduating from UCLA, he was a medical doctor and served as the chairman of the board of Lakeside HealthCare, Inc., a health-care provider.
Richman was elected to the Assembly in November 2000 replacing Republican Tom McClintock and won re-election in 2002 and 2004.
In 2006 he sought the Republican nomination for California State Treasurer but lost to Board of Equalization member Claude Parrish 56%-44%.
With his father, Dr. Monroe Richman, who had also previously held elective office (as a member of the Los Angeles Community College District Board of Trustees), he practiced internal medicine in Sun Valley.