Sergeant First Class Selby was a medic with the Medical Company, 38th Infantry Regiment, 2nd Infantry Division. He was listed as Missing in Action while tending his wounded comrades in South Korea on 12 February 1951. He was presumed dead on 31 December 1953. His remains were not recovered. His name is inscribed on the Courts of the Missing at the Honolulu Memorial.

Selby was awarded the Purple Heart with 2 Oak Leaf Clusters, the Combat Medical Badge, the Korean Service Medal, the United Nations Service Medal, the National Defense Service Medal, the Korean Presidential Unit Citation and the Republic of Korea War Service Medal.