Corporal Walter was a member of Battery A, 57th Field Artillery Battalion, 7th Infantry Division. He was taken Prisoner of War while fighting the enemy near Hagaru, North Korea, on 6 December 1950 and died while a prisoner on 28 February 1951. His remains were not recovered. His name is inscribed on the Courts of the Missing at the Honolulu Memorial.

Walter was awarded the Purple Heart, 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.