Private First Class Larkin was a member of the 32nd Infantry Regiment, 7th Infantry Division. He was seriously wounded by the enemy in North Korea on 23 October 1952 and returned to duty on 28 October 1952. He was Killed in Action while fighting the enemy in North Korea on 1 November 1952.

Larkin was awarded the Purple Heart with Oak Leaf Cluster, the Combat Infantryman Badge, 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.