Rudolf Höss
Höss joined the Nazi Party in 1922, and joined the SS in 1934.  From 4 May 1940 to November 1943, and again from 8 May 1944 to 18 January 1945, he was in charge of Auschwitz.  Before Nazi Germany lost World War II, more than a million people were murdered at Auschwitz.  Höss was hanged in 1947 after he was found guilty at a trial in Warsaw, Poland.