His investigation was not welcomed though; his assistant SS-Stabsscharführer Gerhard Putsch disappeared and the building where evidence files were stored was burned down.[16] Although he could not prosecute the mass extermination of Jews — which, as he explained after the war, was legalized by order of Hitler — he still went on to prosecute the camp commandant Rudolf Höss and the Chief of the camp Gestapo, Maximilian Grabner, for crimes including murder.