Corporal Barnett was a member of Company A, 1st Battalion, 5th Marines, 1st Marine Division. He was Killed in Action while attacking the enemy north of Seoul towards Uijongbu, South Korea on 27 September 1950.

Barnett was awarded the Purple Heart, the Combat Action Ribbon, the Korean Service Medal, the United Nations Service Medal, the National Defense Service Medal and the Korean War Service Medal.