Sergeant Joyner was a veteran of World War II. In Korea, he was a member of Headquarters Battery, 555th Field Artillery Battalion, 5th Infantry Regimental Combat Team. He was Killed in Action while fighting the enemy near Pongam-ni, South Korea, on 12 August 1950.

Joyner was awarded the Purple Heart, the Korean Service Medal, the United Nations Service Medal, the National Defense Service Medal, the Korean Presidential Unit Citation, the Republic of Korea War Service Medal and the World War II Victory Medal.