He served as an assistant United States attorney of the Eastern District of California from 1965 to 1971.

He was the chief assistant United States attorney of Eastern District of California from 1971 to 1974.

Shubb was the United States attorney for the Eastern District of California from 1980 to 1981.

[1] On August 3, 1990, Shubb was nominated by President George H. W. Bush to a seat on the United States District Court for the Eastern District of California vacated by Judge Raul Anthony Ramirez.

Shubb was confirmed by the United States Senate on September 28, 1990, and received his commission on October 1, 1990.