It's a tale as old as time. We've all heard stories involving a potential killer living in our attic who comes down when everyone is peacefully asleep. But this has actually happened.
In Germany in 1922, a farm owner named Andreas Gruber noticed that small things started going missing or being misplaced. His family also heard footsteps while Gruber himself found footprints in his house. A few weeks later, the entire family was found slaughtered in their home. The identity of the mysterious killer remains unsolved.
