In July 2001, German couple Daniel and Manuela Ruda- deeply involved in Satanic and vampire-themed beliefs- lured their friend, 33-year-old Frank Hackert, to their apartment in Witten and brutally murdered him in what they described as a ritual killing. Manuela had filed her teeth into fangs and slept in a coffin, and Daniel claimed he’d received a vision of the number 6667, which he believed meant they should marry on June 6 and kill themselves on July 6 after offering a human sacrifice to Satan.