Sergeant Barnett was a member of Company G, 2nd Battalion, 31st Infantry Regiment, 7th Infantry Division. He was taken Prisoner of War while fighting the enemy in North Korea on 1 December 1950 and died while a prisoner on 29 January 1951. 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 Barnett was awarded the Bronze Star Medal, the Purple Heart, 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.