The son of a U.S. Air Force officer, Bill graduated in 1961 from Yamato High School in Japan, and enlisted in the U.S. Navy. He was honorably discharged in 1965. He served in Vietnam, rising to the rank of petty officer. Cooper was awarded the Navy Commendation Medal with V device and the Navy Achievement Medal with V device. He was honorably discharged in 1975.
William Cooper was murdered 2 months after 9/11.