Sergeant First Class Parra was a forward observer with the 99th Field Artillery Battalion, 1st Cavalry Division. On 2 November 1950, he used a machine gun to delay the Chinese five miles southwest of Unsan along the main road to Anju, North Korea, until he was mortally wounded. His remains were recovered on 16 July 1993 and identified on 23 October 2008. His name is inscribed on the Courts of the Missing at the Honolulu Memorial.

Parra was awarded the Purple Heart, 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.