Complex sentence: He returned to Auschwitz, and in 1945, when the Red Army liberated the camp, Fritzsch has been murdered by the Russians, while the two other high officials, Rudolf Hoess and Arthur Liebhenschel was arrested and later executed.
Split into simpler sentences: He returned to Auschwitz, and in 1945, when the Red Army liberated the camp, Fritzsch was murdered by the Russians. The two other high officials in the camp, Rudolf Hoess and Arthur Liebhenschel, were arrested and later executed.