First Lieutenant Mitchell was a veteran of World War II. In Korea, he was the pilot of a RB-29A Flying Fortress reconnaissance aircraft with the 31st Strategic Reconnaissance Squadron, U. S. Air Force. On 9 November 1950, after flying a photo reconnaissance mission, his aircraft was damaged by MiGs and crashed short of the runway at Johnson Air Force Base, Japan.

Mitchell 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.