'Met' is saying to much, but (since there's been so much here about the likelihood of an SS officer being involved in torture and murder) - my godmother, a brilliant woman, smart, generous, warm, best-ever bullshit detector but wouldn't put you on the spot - was the daughter a former high-ranking SS officer. He was involved in selecting people to be shot during the invasion of Ukraine and his guilt was so manifest that he was sentenced to prison in West Germany in the 1960s, when prosecution of Nazi war crimes was laggard. He maintained all his life that his actions had been legal.
I only met him once, at the funeral of one of his children - a grief-stricken 80-year-old man who kept himself to himself. In my family network, he was widely known simply as 'the Nazi', and he knew that, too.
He was a competent lawyer (like scarily many Nazi officials) and his personnel files (since consulted by historians) describe him as a pleasant man and good conversationalist. He also managed to extract a great deal of emotional labour from his children. He abandoned his wife and five children shortly after the war, but, once he had reestablished contact, felt completely entitled to demand loyalty from them. Decades after the war, he berated my godmother for voting social democrat (ffs), and their relationship, such as it was, finally died when she switched to voting green.
Whether the SS officer mentioned here really tortured people to death is impossible to know - I have a relative with incipient dementia and she's already started making stuff up - but unlikely it is not, and it is not incompatible with him having seemed completely 'normal' for decades.