Yes.
In 1947, in Poland, communist authorities began a series of trials of people accused of participating in mass murder at the Auschwitz concentration camp.
The second of these trials, confusingly called “The First Auschwitz Trial” (Pierwszy Proces Oświęcimski), involved 40 defendants - most of them highly placed officers and administrators in the camp.
Out of the forty defendants, twenty-three were sentenced to death by hanging, six to life imprisonment, seven to 15 years imprisonment, and three to 10, 5 and 3 years imprisonment respectively.
One was acquitted of all charges.
This guy: Hans Wilhelm Münch, seen in the picture wearing the uniform that might as well be synonymous with “war criminal”.
As far as the evidence suggests, Dr. Münch was a card-carrying member of the Nazi party, having joined up out of either genuine belief in their ideals, or self-serving reasons to advance his own career as a doctor and bacteriologist.
In 1943, he was recruited by the SS and sent to assist with medical experiments in Auschwitz. But something strange happened there: the hardcore Nazi/selfish bastard refused to enable the crimes of his superior, Josef Mengele, and - at great personal risk - began assisting the camp’s inmates.
First, he outright refused to participate in the infamous “selections” at the railway platform, which determined who’d be put to work, who’d be experimented upon, and who would be put to death immediately.
Second, he kept Mengele’s victims alive by coming up with elaborate fake experiments, that in reality were just cover for providing people with actual medical treatment, and keeping them from being killed as no longer useful.
And, finally, when leaving the camp ahead of the advancing Red Army, he gave his personal revolver to a prisoner.
And so, in December 1947, while people with every right to hate Nazis described the crimes of 39 defendants in detail, they surprised all the judges and prosecutors by standing up for an SS man and member of the Nazi party who worked for one of history’s greatest monsters.
Nobody really expected that, but the testimonies were so earnest, consistent and came from so many inmates, that even communist prosecutors had to concede their charges were unsubstantiated, and thus Hans Münch was permitted to leave, return to Germany and live out the rest of his life practicing medicine.
So, to sum it up: Yeah. There was a single SS soldier whose turn from evil was so complete that he faced communist justice and lived to tell the tale.
