I remember seeing a documentary on Auschwitz where they talked to survivors and also to some of the guards that ran the camp. It was chilling to see that the guards had no remorse for their actions. Many of the guards managed to avoid jail terms for their crimes.
Some tried to justified it by saying they were following orders, or that's how it was back then. Some didn't really care about what they had done or how they had profitied from the misery inflicted on others.