During World War II, the Institute regularly received human body parts, including eyes and skulls, from Nazi party member Karin Magnussen who studied eye colors, and Josef Mengele (at Auschwitz concentration camp) to use in studies intended to prove Nazi racial theories and justify race-related social policies. After the German capitulation in May 1945, most of the thousands of files and lab material of the Institute were moved to an unknown location or destroyed, and never obtained by the Allies to use as evidence in war crimes trials and to prove or dis-prove the Nazi racial ideology which had motivated mass genocide in Europe. Most of the staff of the Institute were able to escape trial.