Toschi was born to the American family of school janitor Sam and Millie Toschi in
San Francisco and was an alumnus of
Galileo High School. Immediately upon graduation, he joined the
US Army, and became a member of the
24th Infantry Division, holding the
Pusan Perimeter during the
Korean War, honorably discharged in 1952. Returning to San Francisco, Toschi joined the
San Francisco Police Department, where he served from 1953 to 1985. He was assigned to its homicide division from 1966 to 1978. He is best known for his role as a chief investigator in the
Zodiac Killer case, which he and his partner, Inspector Bill Armstrong, began to work on after the murder of taxi driver
Paul Stine. He was also assigned to the
Zebra murders team, and in 1985 received a meritorious conduct award for curtailing the career of a rapist/burglar. Toschi was well known for his style of dress, including bow-ties, 'loud' plaid suits, bounteous curls, and exaggerated trench-coat at a time when investigating officers strove to look subdued
"like G-men". In 1976, he sent anonymous letters admiring his own efforts to
Armistead Maupin, then a writer for the
San Francisco Chronicle; the revelation of that led to him being removed from the case in 1978 and being reassigned to the robbery detail. Shortly after he left the SFPD, Toschi became Director of Security for
St. Luke's Hospital in
San Francisco's
Mission District, and later served the same role for San Francisco's
Pan Pacific Hotel. Toschi was vice president of North Star Security Services in
Daly City. He was a technical advisor to the producers of the 2007 film
Zodiac. Toschi married Carol Bacigalupi in 1957. They had three daughters, Susan, Karen, and Linda. During production of
Zodiac, his family refused to be present or referenced in the film, though his wife was portrayed in the film by
June Diane Raphael. ==In popular culture==