yet again you are showing a lack of knowledge in this matter,so I will attempt will educate you further: The vast overwhelming Jews Gypsies,Russians,Poles and other people the Nazi's deemed "undesirable " killed in the camps were either taken in combat,or were rounded up by the Gestapo,Einsatz Kommandos , Local Nazi Sympathizers or even the German Army in occupied countries and sent to the death camps. they were NOT German citizens and the laws regarding who and who could not own weapons in Germany did not apply to these poor souls.
On a side note: in the camps to reduce the number of guards needed some prisoners became what the Germans termed"Prisoner Functionaries" and the prisoners called them Kapos. These Jews were ARMED with rifles,pistols and sub machine guns and were often even more brutal than the SS guards,to ensure they kept their positions. they shot fellow prisoners,as well as marching them to the Gas Chambers.
sorry mate,but not everything is as cut and dried in this period of history as you would like it to be