Why does Zalachenko and his son have different surnames?
Alexander Zalachenko
Ronald Niedermann
Alexander Zalachenko Swedish pseudonym was Karl Axel Bodin. Karl Axel Bodin was in fact a real person, one of few Swedish people who joined the Nazis in World War II (during which Sweden was neutral). Anyway, Agneta Salander, Lisbeth's mother was never married to Zala and Niedermann is Lisbeth's half brother from another relationship Zala had. So he got his name from his mother who neither she was married to Zala.