Re: Presidential Pardon?
If thisperson's military records were not destroyed in the 1970's archive fire then you should be able to discover the basic facts of the charge by obtaining his file from NARA.
Prior to the Korean War troops were tried under the Articles of War. I'm not familiar with this system but I assume that it was similar to the later Universal Code of Military Justice.
UCMJ trials are conducted by the Judge Advocate General's Corp in the U.S. Army. Their proceedings, I would think, are in an archive somewhere. If the JAG Corp doesn't have the records they probably know where they are.
There is also the possibility that there are civilian records of the pardon in the records of the president's office.
Since this is such an unusual circumstance you'll probably have to search a few dead ends to find out where the records came to rest.
Sorry, I can't be more specific.