He served as a deputy district attorney of Fresno County from 1967 to 1969, and an adjunct professor at Humphreys College Laurence Drivon School of Law from 1968 to 1969.
He was a Pro tem settlement conference judge, Superior Court of California, County of Fresno in 1989.
[4] Wanger was nominated by President George H. W. Bush on January 8, 1991, to a seat vacated by Judge Milton Lewis Schwartz.
[5] The highly technical scientific disputes Wanger was forced to resolve would require him to rely on his own appointed expert witnesses and often to issue rulings that were hundreds of pages long.
[6] During the bitterly contested delta smelt case, Judge Wanger drew national attention when he lengthily ridiculed a testifying government scientist for being a "zealot".