On the night of 31 March 1922, someone lured four members of the Gruber family to a barn on their farm outside Munich, one at a time, and killed each of them with a mattock. The killer then went into the house and killed a young boy and the family’s newly arrived maid. Six people died that night. Whoever did it didn’t leave. They stayed on the farm for several days afterward, feeding the livestock and using the fireplace, while the bodies remained where they’d fallen. More than a century later, the case remains officially unsolved.
A Farm With Warning Signs Already in Place
The Hinterkaifeck farmstead sat roughly 70 kilometres north of Munich, near the hamlet of Kaifeck. Even before the murders, the household had a documented history investigators would later treat as relevant: in 1915, Andreas Gruber, the family patriarch, and his daughter Viktoria Gabriel were convicted of incest, resulting in a one-year prison sentence for Andreas. In the months before the killings, the family’s maid at the time, Kreszenz Rieger, quit her position, telling others the house was haunted. In March 1922, Andreas himself reported finding a Munich newspaper he hadn’t purchased, and footprints in the snow leading from the nearby forest to the farmhouse, with no matching tracks leading back out. Like the Isdal Woman case in Norway, the physical evidence here is unusually rich, yet it has never been enough to produce a name or a conviction.
The Murders and the Days That Followed
On 31 March, a new maid, Maria Baumgartner, arrived at the farm. That evening, Andreas, his wife Cäzilia, their daughter Viktoria, and Viktoria’s seven-year-old daughter (also named Cäzilia) were each drawn to the barn individually and killed. The perpetrator then entered the house and killed Viktoria’s two-year-old son, Josef, along with Maria. Court physician Dr. Johann Baptist Aumüller’s later examination found the elder Cäzilia had suffered seven blows to the head, and Viktoria nine star-shaped wounds. Disturbingly, evidence indicated the younger Cäzilia had been alive for several hours after the attack, having torn out tufts of her own hair before she died.
What happened next is what makes the case genuinely strange rather than simply brutal. For several days, someone remained on the property. Coffee sellers visiting on 1 April found no one home, though a witness reported seeing two figures near the forest edge that same day. On 4 April, a mechanic spent four and a half hours at the farm repairing an engine without encountering the family at all. It wasn’t until later that day that a search party discovered the bodies in the barn.
An Investigation Undermined From the Start
The original 1922 investigation was compromised almost immediately. Onlookers reportedly entered the crime scene, cooked meals in the house, and moved evidence before police could properly document it. Investigators dismissed robbery as a motive after finding large sums of money left untouched inside the home. The case was formally closed without a conviction in 1955, and final interrogations related to it were conducted as late as 1986, over sixty years after the murders.
Suspects, Then and Now
Neighbour Lorenz Schlittenbauer, who led the search party that found the bodies, has remained one of the most persistently suspected individuals, though never charged. Other theories have ranged from Viktoria’s husband Karl Gabriel, despite fellow soldiers reporting they’d seen his body on a WWI battlefield years earlier, to a theory proposed by author Bill James linking the murders to Paul Mueller, a suspected serial killer active in the United States, based on similarities in method. None of these theories has ever been confirmed.
In 2007, fifteen students at the Fürstenfeldbruck Police Academy reexamined the case using modern investigative methods. Their consensus was that the original 1922 investigation had actually been meticulous for its time, but critically hampered by the absence of tools like fingerprint analysis that didn’t yet exist. The students reportedly reached agreement on a primary suspect among themselves, but chose to withhold the name out of consideration for the suspect’s living descendants.
A Farm That No Longer Exists
The Hinterkaifeck farmhouse was demolished in 1923, less than a year after the murders. The mattock used in the killings, which had belonged to the family itself, wasn’t recovered until it turned up in the attic during that demolition. More than 100 years on, the case remains one of the coldest unsolved crimes in German history, not for lack of suspects, but for a persistent lack of anything that could turn suspicion into proof.