Corporal Gayles was a member of Battery A, 503rd Field Artillery Battalion, 2nd Infantry Division. He was taken Prisoner of War while fighting the enemy in South Korea on 12 February 1951 and died while a prisoner on 31 May 1951. His remains were not recovered. His name is inscribed on the Courts of the Missing at the Honolulu Memorial.

Gayles was awarded 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.