The Hinterkaifeck Murders took place in 1922 at a remote farmstead in Bavaria, Germany. Six people—Andreas and Cäzilia Gruber, their daughter Viktoria Gabriel, her two children, and their maid—were brutally murdered with a mattock. In the days leading up to the crime, the family reported strange occurrences, like footsteps in the snow leading to their home but not away, missing keys, and unsettling noises in the attic.

Despite multiple investigations, no killer was ever identified, and the case remains one of Germany’s most chilling unsolved mysteries.