1. The Hinterkaifeck Murders (Germany, 1922)
The Hinterkaifeck murders are one of the most chilling and mysterious crimes in history. In 1922, six members of the Gruber family were brutally murdered on their isolated farm in rural Germany.
What makes this case terrifying is the fact that the killer(s) remained on the property for days after the murders, using the house, eating the food, and even feeding the animals. To this day, the identity of the killer remains unknown, and the eerie silence surrounding the case continues to haunt those who hear it.