Born in Raton, New Mexico, Warren received a Bachelor of Arts degree from Macalester College in 1950, a Master of Arts from the University of Minnesota in 1951, and a Juris Doctor from the University of Wisconsin Law School in 1956.

He served in Europe during World War II and was wounded in France, receiving a Purple Heart.

[1][2] Warren was nominated by President Richard Nixon on August 8, 1974, to a seat on the United States District Court for the Eastern District of Wisconsin vacated by Judge Robert Emmet Tehan.

He was appointed a judge of the United States Foreign Intelligence Surveillance Court of Review by Chief Justice William Rehnquist in 1989, serving until 1996.

His service terminated on August 20, 1998, due to his death in Milwaukee.