Joachim Peiper (30 January 1915 – 14 July 1976) was a German Schutzstaffel (SS) officer and a Nazi war criminal convicted for the Malmedy massacre of U.S. Army prisoners of war (POWs). During the Second World War in Europe, Peiper served as personal adjutant to Heinrich Himmler, leader of the SS, and as a tank commander in the Waffen-SS.