Winnie Heller is an unusual detective, she has psychological issues, probably some sort of autism, she sees things others don't, but she doesn't get along well with other humans, especially her colleagues and she keeps breaking the rules.
I doubt that someone like her could really make a career in the German police, that's why I think this series is not very realistic, but if you put that aside, this series is very entertaining, the cases are solved in a clever way and I'm really looking forward to the next installment.