On the night of November 5, 1933 Axel Kjellberg and his maid Karin Holmberg were killed in Kjellbergs house in Kölfors, Enåker parish, Uppland, Sweden.
In 1934, Erika Mathilda Blomqvist in Hällby outside Västerfärnebo was killed in a way that afterwards has been described as the perfect crime.