Should you travel to Munich in Germany, don't traverse around 43 miles north of the city. That's where you'd find Hinterkaifeck, a small farmstead once home to the unfortunate Gruber family. Father Andreas, his wife Cäzilia and the rest of their family were brutally murdered there by an unknown attacker who was never caught by police.
The authorities interviewed and interrogated several known criminals in the area for years, but found nothing linking them to the atrocity. 35-year old Viktoria Gabriel, her 2 young children and the farm's maid were also found slaughtered. It wasn't until neighbours in the surrounding area noticed 7-year old Cäzilia (taking the name of her grandmother) hadn't been to school for several days that an investigation was launched.
In days leading up to the massacre, Andreas had told neighbours about footprints he'd discovered. The trail led from the forest to the farm, but there weren't any going the opposite direction. It's believed that most of the Gruber family were murdered in the same barn, and were lured there one-by-one by the mystery butcher.