The SS committed an atrocity like this in WWII against American troops, the Malmedy Massacre. We hunted down and prosecuted those war criminals. Those who did this should be hunted down and exterminated like the subhuman vermin they are.
The Germans set them loose after 10 years in prison. Joe McCarthy had a hand in their release. Meanwhile, Japanese officers guilty of the same thing were hanged, almost to a man.