He received a Bachelor of Science in Education degree from Boston State College in 1965 and a Juris Doctor from Georgetown University Law Center in 1970.

Shea was a law clerk to Judge Harold Petrie of the Washington Court of Appeals, Division II from 1970 to 1971.

He was nominated to the seat vacated by Judge Alan Angus McDonald.

He was confirmed by the United States Senate on March 27, 1998, and received his commission on April 8, 1998.

Shea assumed senior status on June 7, 2012.