There’s something about unsolved murders that captures the public’s imagination. The longer a case runs unsolved, or the more bizarre the details, the more likely a case is going to live on in the form of books, documentaries, podcast episodes, and the minds of true crime lovers.
The murders at the Hinterkaifeck farmstead fit this mold to a tee.
In 1922, five members of the Gruber family and their new maid were brutally massacred on the property. In the following hours, their murderer remained in the house, even going so far as to feed the livestock. The case, which is nearly a century old now, remains unsolved.
An Isolated Farm
The property is only known as Hinterkaifeck in media releases; technically, it belonged to the village of Gröbern as house number 27 ½. They call it that because it was located about 1 kilometer north of the tiny hamlet of Kaifeck (the prefix “hinter” means “behind”).
The owner was then 63 year old Andreas Gruber – he lived there with his 72 year old wife Cäzilia, their daughter Viktoria Gabriel who was recently widowed, and Viktoria’s children Cäzilia and Josef, ages seven and two, respectively. To avoid confusion, the two Cäzilias will be denoted as as “C. Gruber” and “C. Gabriel.”
Also living on the property was their new maid, Maria Baumgartner, who had only arrived on the afternoon before the murders. She was escorted by her sister, who is assumed to be the last person who had ever seen the occupants of Hinterkaifeck alive.
According to neighbors and friends of the family, Andreas was complaining of strange occurrences on the farm before the murders. Six months before, their previous maid quit after claiming that she heard strange noises coming from the attic; she believed that the house was haunted and refused to stay.
Earlier that month, Andreas found a newspaper from Munich in the house – he couldn’t remember buying it, and initially believed that the postman had simply lost it. However, it was later found out that that was impossible, because no one in the vicinity subscribed to that particular newspaper.
Just days before the attack, Andreas told his neighbors that he’d discovered tracks in fresh snow leading from the forest into his house. While this by itself was not unusual, he was unsettled that there weren’t any tracks leading away. Around the same time, a set of the family’s house keys went inexplicably missing. During the night, the family thought they heard footsteps up in their attic, but Andreas found no one when he searched the building.
Although Andreas is reported to have told multiple people about these occurrences, he refused to accept any help with the matter, and the details went unreported to police until it was much too late.
Considering the antiquity of this case, the exact events of that night are impossible to recreate with any certainty. However, there are a few facts that are clear after the investigation.
It appears that in the late evening of March 31, the residents of Hinterkaifeck were lured to the barn one at a time. Viktoria Gabriel has been determined as the first victim via crime scene recreations, followed closely by C. Gruber, Andreas, and finally C. Gabriel. The perpetrator, or perpetrators, bludgeoned the victims to death with a mattock – a farming tool similar to a pickaxe that is presumed to have come from the property.
It’s uncertain whether the family went out to the barn as part of their regular routine, or if something unusual made them go out to investigate. Later experiments by police proved that screams inside the barn could not be heard on the rest of the estate, so it is unlikely that the other victims knew of the fate of their family members before they reached the barn.
The killer then walked through the stable and into the house, where he used the same weapon to kill the maid, Maria, in her bedchamber. 2-year-old Josef is presumed to have been the last victim; he was bludgeoned while asleep in his bassinet, located in his mother’s bedroom.
Discovery and Investigation
Four days passed between the murders and the discovery of the bodies. On April 1, a pair of coffee sellers arrived to place an order; when no one responded to knocks on the door and windows, they decided to leave, but not before noticing that the gate to the machine house was open.
For the next few days, C. Gabriel was absent without excuse from school, and the family failed to show up for church on Sunday. After a repairman noticed that there was no activity on the farm, the village guide Lorenz Schlittenbauer – remember him, we’ll talk about him later – sent his two sons to check on them. When they returned saying they didn’t see anyone, Schlittenbauer went with two other men and discovered the mostly-concealed bodies in the barn and home.
Inspector George Reingruber and his colleagues from the Munich Police Department were dispatched to investigate the killings. The day after the discovery, court physician Johann Baptist Aumüller performed the autopsies in the barn where the bodies were found.
He determined that a mattock was the most likely murder weapon, even though such an item was not found on the property. Evidence also showed that C. Gabriel had been alive for several hours after the attack, tearing her hair out in tufts while lying next to the bodies of her mother and grandparents. Aumüller also removed the victim’s skulls and sent them to Munich, where they were examined by clairvoyants.
Initially, police suspected that the motive for the murders was robbery, and interrogated a number of traveling craftsmen, vagrants, and residents of nearby villages. However, a large amount of money was later discovered in the house, in such a place that it would have been easily discovered if robbery was the intention.
It hadn’t even been touched, so the robbery theory was abandoned. It was also clear that the perpetrator stayed at the farm for several days after the murders. The cattle had been fed, the entire supply of bread had been taken from the kitchen, and slices of meat had recently been cut from the supply in the pantry.
Neighbors also reported smoke coming from the chimney throughout the weekend before the bodies were discovered. It is assumed that the perpetrator was already inside the house when the murders occurred, possibly hiding in the attic. This assumption is because of the stories Andreas Gruber was telling his neighbors, though there is little evidence of it.
The investigation, by all accounts, was badly botched. There were only five photographs ever taken of the crime scene; two of the bodies in the barn, one of Maria in her bedchamber, one of Josef in his bassinet, and an outside view from the yard. No fingerprints were ever taken. Later on, the skulls of the victims, which were stored in a justice building in Augsburg, were lost – it’s thought that they were destroyed during Allied bombings in WWII.
Suspect: Karl Gabriel
There have been more than 100 suspects in the case that have been questioned throughout the years, with the last interrogations having been conducted in 1986. However, there are two that stand out in the lore surrounding these terrible crimes.
The first and foremost in the minds of conspiracy theorists is Karl Gabriel – Viktoria Gabriel’s husband, and the father of C. Gabriel. According to all official records, he was a soldier, and was killed during WWI, in December 1914. However, his body had never been recovered, and after the murders, people began to speculate that he hadn’t died at all, and instead swapped identities with another fallen comrade.
The reasoning behind this is that Viktoria gave birth to Josef illegitimately after her husband’s death – according to most rumors, he was the product of an incestuous relationship between Viktoria and her father Andreas.
This relationship was documented by the courts and well-known in town, but there are alternate possibilities for who fathered the child that we’ll cover later on. Some theorized that Karl knew of this relationship, or found out before his supposed “death”, and returned to kill the family out of revenge.
Despite the popularity of this theory, soldiers from Karl’s regiment testified that his death was legitimate, and police were inclined to believe them. There were repeated claims that people had met Gabriel after the murders or claimed to be able to confirm that he’d indeed switched places with a dead comrade on the front. These claims remain unsubstantiated in all cases, but there is one more unusual story about Karl Gabriel.
At the end of WWII, prisoners of war from the Schrobenhausen region who were released prematurely from Soviet captivity claimed that the man who’d sent them home had been a Bavarian-speaking Soviet officer who claimed to be behind the murders at Hinterkaifeck. These statements were later revised by some of the men, diminishing their credibility, but many who subscribe to the theory believe that this officer was in fact Karl Gabriel – those who claimed to have spoken with the man after his death said that he’d wanted to go to Russia.
In any case, there is no way to verify whether or not Karl Gabriel died in 1914, but even if there was, there would be no evidence to support his involvement in the murder of his family.
Suspect: Lorenz Schlittenbauer
The other prime suspect is Lorenz Schlittenbauer, one of the men who discovered the bodies. In 1918, shortly after the death of his wife, Lorenz is said to have become entangled in a relationship with Viktoria Gabriel. He is the other suspected father of Josef – the timeline appears to match, and his initials appeared on the boy’s birth certificate.
The theory states that he could have killed the family because Viktoria was coming after him for child support. Suspicions rose in the locals because of his odd behavior following the killings. At the time he and his friends arrived to investigate the farmstead, they had to break a fate because all of the doors and windows to the house were locked.
However, after finding the bodies in the barn, his friends stepped out to recover from shock; Schlittenbauer continued through the stable, and the other men clearly heard him unlock the front door with a key.
There is speculation that this could have been the house key that went missing a few days before the murders, but it was also possible that Schlittenbauer could have had a key for any number of other reasons, such as his relationship with Viktoria. He also disturbed the bodies at the scene, ruining the initial investigation and possibly affecting any later reconstruction attempts. He claimed that he did this while looking for his son, giving credence to the idea that he was, in fact, Josef’s father.
Even years later, suspicions remained on Schlittenbauer. According to a report found in the case files, a local teacher named Hans Yblagger surprised Schlittenbauer at the remains of the demolished Hinterkaifeck farm in 1925. Frightened and confused, Schlittenbauer is said to have commented that the perpetrator had tried to bury the bodies in the dirt floor of the barn but couldn’t because the ground had been frozen.
This seemed to be a fact that only the perpetrator would know, but it should also be noted that Schlittenbauer was a neighbor and familiar with the local lands – he would have known that the ground was frozen due to the weather at the time, and could have been making an educated guess.
Before his death in 1941, Lorenz Schlittenbauer conducted, and later won, multiple civil lawsuits for slander against people who had described him as the “murderer of Hinterkaifeck.” Despite the apparent wealth of circumstantial evidence against him, nothing conclusive has ever been found to state that he was involved in the murders.
Despite repeated arrests and interrogations, no definitive culprit for the murders has ever been found, and the files were closed in 1955. In 2007, the students of the Polizeifachhochschule or Police Academy in Fürstenfeldbruck examined the case using modern techniques and concluded that it is impossible to definitively solve it, considering that so much time has passed and evidence has been lost. Despite this, however, the students did identify a prime suspect – they have not named them out of respect for relatives that are still living.
The Hinterkaifeck murders have been the subject of numerous books, documentaries, and podcast episodes over the years. Most are in German, such as the books written by Munich journalist Peter Leuschner, which were both entitled Hinterkaifeck: Der Mordfall, Spuren eines mysteriosen Verbrechens and published in 1979 and 1997 respectively – the second is an extension of the first in which he quotes the original police files.
In the last chapter of The Man from the Train by Bill James and his daughter, Rachel McCarthy James, the authors briefly discuss the Hinterkaifeck murders, explaining the possibility that the crimes could have been committed by Paul Mueller, the man they believe killed multiple families in the United States under similar circumstances, including the infamous Villisca Axe Murders. The evidence, however, is slim to none.