About the story of killing prisoners - I have to answer, as I wrote it, and if you read it closely, you see it stays unknown until after the war.
If you read it still more closely, you may understand why - the killing was done in the best place to mask it: in a cemetery.
And, what's more, in a cemetery which was the center of the defense of the town a couple of days later. And, as such, it was shelled and bombed. And after that, the Germans left the civilians bury the dead.

I didn't gave these precisions because my story was about a young lieutenant, an old colonel and a neutral journalist, and I didn't feel "technical" precisions were necessary.
But I am going to add them.

Frank