Sergeant First Class Demoll was a member of Company I, 3rd Battalion, 19th Infantry Regiment, 24th Infantry Division. He was seriously wounded by the enemy in South Korea on 24 September 1950 and returned to duty on 14 December 1950. He was taken Prisoner of War while fighting the enemy in South Korea on 4 February 1951. He was presumed dead on 5 March 1954. His remains were not recovered. His name is inscribed on the Courts of the Missing at the Honolulu Memorial.

For his leadership and valor, Sergeant First Class Demoll was awarded the Bronze Star Medal, the Purple Heart with 4 Oak Leaf Clusters, the Combat Infantryman's Badge, the Prisoner of War Medal, 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.