He was in private practice in
San Francisco,
California from 1928 to 1932. He was an assistant district attorney of the City and County of San Francisco from 1932 to 1933, and an
Assistant United States Attorney of the Northern District of California from 1933 to 1944. He returned to private practice in San Francisco from 1944 to 1961, also serving on the
San Francisco Board of Supervisors from 1958 to 1961. During his time as an attorney, he represented
death row inmates
pro bono.
Federal judicial service On September 14, 1961, Zirpoli was nominated by President
John F. Kennedy to a new seat on the
United States District Court for the Northern District of California created by 75 Stat. 80. He was confirmed by the
United States Senate on September 21, 1961, and received his commission the following day. He assumed
senior status on September 30, 1975, serving in that capacity until his death on July 10, 1995, in San Francisco. == Personal life ==