Private First Class Coker was a member of Headquarters Company, 3rd Battalion, 31st Infantry Regiment, 7th 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 15 April 1951. His remains were recovered on 20 November 2000 and identified on 3 May 2011. His name is inscribed on the Courts of the Missing at the Honolulu Memorial.

For his leadership and valor, Private First Class Coker was awarded the Bronze Star Medal, 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.