Records for U. S. Army Guard at Nurnberg war trials

My wife's uncle PFC William H. Mitchell, Jr. served in the 26th Infantry Regiment during WWII. He fought in the Battle of the Bulge (possibly as part of the 79th Infantry) and was shot one inch below the heart, yet survived. After the war, he re-enlisted so he could stay in Germany as he wanted to marry a German girl. He was assigned to serve as a guard at the Nurnberg war Trials. He guarded many of the war criminals including Rudolph Hess and escorted him to the trial daily. Are there records which could reveal insight into his life as a guard? Have seen numerous websites about the Nurnberg war trials, but have not found anything about him nor do we see a picture of him (We have a picture of him in his WWII uniform to compare faces to.)