After completing high school Bob joined the United States Navy in 1946.

Corbin started working as a Maricopa Deputy County Attorney in 1958.

He was elected to the Maricopa County Board of Supervisors in 1972, and Attorney General in November 1978 and served until his retirement in January 1991, holding that office longer than any other elected official.

Corbin prosecuted Republican Governor Evan Mecham for misusing campaign contributions.

[3] In 1987, Corbin indicted former congressman Sam Steiger for extorting a member of the parole board.