Adjutant Karl Höcker's postwar trial documented his culpability in mass murders committed at this camp. "On 3 May 1989 a district court in the German city of Bielefeld sentenced Höcker to four years imprisonment for his involvement in gassing to death prisoners, primarily Polish Jews, in the concentration camp Majdanek in Poland. Camp records showed that between May 1943 and May 1944 Höcker had acquired at least of Zyklon B poisonous gas for use in Majdanek from the Hamburg firm of Tesch & Stabenow." In addition, Commandant Rudolf Höss of Auschwitz wrote in his memoirs, while awaiting trial in Poland, that one method of murder used at Majdanek (KZ Lublin) was Zyklon-B.