Sergeant First Class Mendoza was a member of Company L, 3rd Battalion, 224th Infantry Regiment, 40th Infantry Division. He led a successful attack against an enemy automatic weapons position near Chung-bang Pyong, North Korea, on 18 February 1952. He was Killed in Action during this attack. His remains were not recovered. His name is inscribed on the Courts of the Missing at the Honolulu Memorial.

For his leadership and valor, Sergeant First Class Mendoza was awarded the Silver Star Medal, the Bronze Star Medal, the Purple Heart, the Combat Infantryman's 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.