Prisoners
They would mostly be jews as prisoners that was their main target their were some Germans that they thought weren't loyal or enemy soldiers caught in the war by around the time it got liberated their was 10,000 prisoners in Buchenwald the prisoners would be tortured, experimented on, hanged in front of the building for scare tactics, worked to death shot, and ect. the germans were trying to break the prisoners to where you wanted to be dead