Watch FMovies. The story of Austrian, Johann "Jack" Unterweger (1950-1994), who wrote a book about his criminal past while serving a life term in prison for assault. In 1974, Unterweger murdered 18-year-old German citizen Margaret Schäfer by strangling her with her own bra, and in 1976 was arrested and sentenced to life in prison. And that was only the beginning... Epsidode 1:4 of "Serial Killers".