The Waffen-SS were combat trained and were sent to fight in campaigns against France, Poland and the Sudetenland. The personnel responsible for running the concentration camps were generally recruited from this branch (sometimes wounded soldiers etc) and the Allgemeine-SS, but by 1942 all were considered Waffen-SS for administration purposes. Most staff were rotated
around various camps, which meant that in terms of culpability, there was little excuse for personnel not knowing the extent of the genocide taking place. In 1945, the Auxiliary-SS were established in a desperate attempt to keep the camps running alongside the approach of Allied forces. These people had little training or equipment and their presence at the camps when they were liberated meant they were held responsible when in some cases they had only been there for a few days or weeks.
It is also worth knowing about the branch of the SS known as ‘Einsatzgruppen’, or ‘Death Squads’. They would be assigned to perform mass killings; by the end of WW2 they bore responsibility for the deaths of over 1,000,000 people. These massacres often took the form of mass shootings, in countries such as Poland, Czechoslovakia and the Soviet Union. They would also arrange transportation to death camps.