I saw this over at The Oddment Emporium, wonderfully fascinating case:
(Former farmstead from Southeast, Source: Wiki)
(All of the text is from the Wiki article)
Hinterkaifeck, a small farmstead situated between the Bavarian towns of Ingolstadt and Schrobenhausen (approximately 70 km north of Munich), was the scene of one of the most puzzling crimes in German history. On the evening of March 31, 1922, the six inhabitants of the farm were killed with a pickaxe. The murder is still unsolved.
(Body of new maid, Maria Baumgartner, in her bedroom. The previous maid quit because she claimed the house was haunted. Source)
A few days prior to the crime, Andreas Gruber told neighbours about discovering footsteps in the snow leading from the edge of the forest to the farm; however, there were none leading back. He also talked about hearing footsteps in the attic and finding an unfamiliar newspaper on the farm. Furthermore, one of the two existing house keys went missing several days before the murders, but none of this was reported to the police.
(Bedroom of Viktoria and children, photographed morning of 4/5/1922, Source)
It is believed that the older couple, as well as their daughter Viktoria and her daughter Cäzilia, were somehow all lured into the barn one by one where they were slaughtered brutally. The perpetrator(s) then went into the house where they killed two-year-old Josef who was sleeping in his cot in his mother’s bedroom, as well as the maid, Maria Baumgartner, in her bed-chamber.
(Bodies in barn encountered by first police officers on the scene, Source)
The day after the discovery, on the 5th of April, court physician Dr. Johann Baptist Aumüller performed the autopsies in the barn. It was established that a pickaxe was the most likely murder weapon. The corpses were beheaded, and the skulls sent to Munich, where clairvoyants examined them without result. The autopsy also showed that the younger Cäzilia had been alive for several hours after the assault. Lying in the straw, next to the bodies of her grandparents and her mother, she had torn her hair out in tufts. The skulls were never actually returned to the bodies and the entire family has been buried without heads. The traces of the skulls have been lost in history. They very likely were destroyed when the forensic department in Nuremberg burned down during WWII.
It is believed that the perpetrator(s) remained at the farm for several days – someone had fed the cattle, and eaten food in the kitchen: the neighbours had also seen smoke from the chimney during the weekend – and anyone looking for money would have found it. But why, if they were not looking for money, would the perpetrators stay there for so long and keep up the appearance that someone was alive?
Much more about suspects and theories at Armchair Detective!
Also, there is a movie out there directed by Esther Gronenborn I am going to try to locate. It stars Benno Fürmann who I recognize from the movie Autopsy. A cursory search has turned up zilch but I'll keep at it. Hopefully will excavate something with subtitles. Note to self: Learn German.