Did they have a fair trial? Did they have any rights when they got arrested?
Due process was thoroughly eroded by the establisment of the Sondergerichte or special courts in 1933. At first they only handled cases of treason and sedition but by 1938 they were responsible for judging any crime that the state prosecutor deemed necessary. The main characteristics of these courts were: very speedy trials, no appeal, no jury, and verdicts based on gesundes Volksempfinden. The latter phrase is extremely hard to translate as it is deeply embedded in nazi ideology which stressed the supremacy of the will of the Volk or (German) people in all areas of life, which in practice meant the will of the nazi party, as the embodiment of the people. It basically means that the verdict had to be in tune with the feelings of the community of the people (read: the party). This evidently opened the door wide for abuses and draconian sentences. Death sentences for even minor crimes, such as the theft of a small amount of food, during the last years of the war were very common. It is estimated that the Sondergerichte handed out over 10,000 death sentences, as well as very long prison and indefinite concentration camp sentences.
At the Nuremberg Justice Trial in 1948 these special courts were condemned among other charges, for their involvement in the "euthanasia" programme that targeted people with disabilities, and in the persecution of the Jews.