A former Nazi SS guard has been sentenced to four years' jail for complicity in the 1944 killing of German Communist Party leader Ernst Thaelmann, ending a 25-year struggle for justice by the murdered man's daughter. Former Buchenwald concentration camp guard Ernst Otto, 74, was found guilty by the West German Krefeld Regional Court guilty of aiding and abetting the A murder of Thaelmann, who led the Party in the late 1920s and 1930s and was an arch-rival of Hitler. March 01, 1932.