On 6 March 1945 Rothkirch, still commanding officer of LIII Corps, wandered into U.S. lines and was taken prisoner west of Coblenz, Germany.

[2] He was interned at Trent Park, an English prison camp in North London for high-ranking German officers.

While stationed in General Government, Rothkirch und Trach became aware of mass shootings by the SS (Schutzstaffel).

In its review of Soldaten ("Soldiers") by historian Sönke Neitzel and social psychologist Harald Welzer (a book based on secret recordings of German POWs by the Allied intelligence), Der Spiegel reports: "Many Wehrmacht soldiers became witnesses to the Holocaust because they happened to be present or were invited to take part in a mass shooting.

The fact that the people involved did not try to keep their activities a secret demonstrates how much the perpetrators took for granted the "mass shootings of Jews," as one of the POWs in Trent Park called it.