Upvote:4
It seems that the Nazis employed a wide range of various legal tricks and arguments to prosecute their enemies and victims. These include:
Preventive measures due to various extraordinary legislation. These were used mostly against their political enemies, such as Communists.
Protective custody. A person was forced to sign a request to be imprisoned "voluntarily" because their life was in danger when free. The Nazis first created the danger and then required people to ask themselves be imprisoned, otherwise the police said they could not guarantee the protection.
According the law, Jews who left Germany for another place of living ceased being German subjects. Nazis employed this law when they mobilized Jews for labor service outside Germany during the war. Upon crossing the German border their property was confiscated and they were no longer considered subjects of the state.
Prosecuting stateless Jews. Some Jews who lived outside Germany could not prove their citizenship of the respective countries, especially in rural areas. Upon German occupation, such Jews were summarily executed because no country recognized them as their citizens. At the same time Jews who could prove their citizenship were spared for a while.
Issuing amnesty orders to the SS. Hitler signed a large number of amnesty orders to the SS personnel who were involved in the atrocities. So that even if they committed crimes according the current law, they were spared of any responsibilities.
In all, a German Jew who managed to remain legally in Germany for the duration of the war, would be most likely spared of the hostilities. The most difficult thing for him would be to avoid conscription to the labor service, which was a disguise for transporting Jews to concentration camps and gettos outside Germany.
In memoirs some German Jews who managed to remain legally in Germany for the duration of the war, recall that many police officers were pointedly polite with them when seeing they were Jews.
In general, the policy of the concentration camps in the occupied territory definitely contradicted the Hague convention of 1907, to which Germany was a signatory.