The Suspected Murderer

Andreas Gruber, 11.09.1858 - 01.04.1922


1. Viktoria Gabriel

Died from 9 holes in the skull on the right side of the head.


2. Cäcilia Gruber

She was found to have 8 holes in the right side of the skull.


3. Maria Baumgartner

Killed by at least one hole in the skullcap. Had additional injuries to the face (on the right side of the head).


4. Josef Gabriel

Died from a single powerful blow to the right side of his skull.


5. Cilli Gabriel

One hole from the mattock in the right side of the face. In addition, the child's mouth and jaw were smashed with a iron band to silence her. The fatal injury was inflicted on her with a pocket knife (throat slit). The pocket knife, which was hidden together with the iron bandf on top of the hayloft, belonged to Andreas Gruber.

Weapons of the Crime

These illustrations are faithful reproductions according to witness statements

Mordwaffen von Hinterkaifeck

(1) Faithful replica according to the testimony of Georg the farmhand. He was working on the Hinterkaifecker farm at the time and observed how Andreas Gruber mounted the screw thread on the mattock. Important: The screw protruded on both sides. This meant that the length could be lengthened or shortened as desired depending on how far it was needed to penetrate the intended target. (Adjusting the depth.) 

(2) and (3) Duplicates, according to the witnesses. 


1 Mattock

Andreas Gruber himself mounted the clamps and the protruding 8mm threaded screw on the mattock. The screw protruding upwards in the picture was deliberately placed in such a way that when it struck the pig's skull, it deliberately caused brain death (similar to a bolt gun). This required a lot of practice, a lot of experience and precise aiming of the deer hoe (the weighted head of the tool).  

2 Pocket Knife

The wound that led to Cilli's final death was inflicted with a pocket knife. Andreas Gruber owned such a knife, which he carried with him at all times.

3 Iron Band

Cilli's screams were silenced on the night of the murder with a iron band. Andreas Gruber was in possession of such an iron band.

All the murder weapons were already in the yard BEFORE the night of the murder. The murder weapons (fig. 1, 2 and 3) were so well hidden by the murderer that they only came to light when the yard was demolished.

Evidence & Clues

The Evidence

Mordwaffe Hinterkaifeck Reuthaue

The curious murder tool convicts the killer 

Andreas Gruber (A.G.) was the unlawful owner of the mattock. He stole the tool years before from his neighbour, the local voluntary town spokesman Lorenz Schlittenbauer. Afterwards, A.G. rebuilt the mattock with his own hands. He clamped the blade with two iron clamps so that it was firmly fixed.  Finally he secured everything together with a continuous 8mm thread and two locking nuts. 

The mattock (see original replica on the right) was a simple but ingenious construction of A.G.'s own.

The long, flat blade was used for removing weeds, and the threaded screw, which protruded 30mm (see picture) was used as a bolt for killing pigs. Inevitably, he must have acquired the striking technique and anatomical knowledge there. For A.G. the mattock was a kind of manual hand-bolt striking implement. If the protruding thread was too short to kill the animal, one simply loosened both lock nuts and thus changed the length of the thread as desired. Then both lock nuts were tightened again. 


The victims were killed in the same way as the pigs (see picture below).


The mattock couldn't be too heavy. It had to lie well in the hand so that it could be used for precise killing. Being too heavy would lead to the tool being awkward and imprecise. The blow was always equally powerful and measured, regardless of whether the victim was standing or already lying on the ground. So the person who struck with the protruding screw must have been familiar with the effect.
Because when the mattock was first used, the murderer already knew how and where he could fatally injure people with the screw.

It was not only the precise and careful striking with the threaded screw that required practice, but also the quick extraction from the skull had to be practised. If the victim fell to the ground during the first blow and the thread was not pulled out in time, it could be bent by the falling weight or the mattock could be torn out of the hand of the performer.


The impact of this special design was known to the killer.


An untrained person would not hit his target (head) at all, because the 8mm thread is about 150mm behind the assumed point of impact.
An untrained person would have assumed to hit with the heavy metal head of the tool rather than the screw further up from it. 

Despite the stressful situation, however, the killer struck in a measured and controlled manner. See Viktoria's skull: 9 focused precision blows without shattering the skull.



Andreas Gruber killed his pigs as shown in the symbolic picture below.


Andreas Gruber Schweine töten Mörder Hinterkaifeck

In this photo, however, the pig must first be stunned with a tool similar to the mattock. If the stunning is successful, brain death must be induced immediately afterwards with the other side of the tool, the sharpened spike. If the animal wakes up again immediately after stunning and jumps away, this would be a disaster for the farmer and the slaughterer. Due to the stress the animal suffers, the meat would overacidify and become tough.

With Andreas Gruber's mattock, it was possible to kill two birds with one stone, so to speak: stunning and killing the animal at the same time. When striking the skull in the middle above the pig's eyes, the 8mm thread penetrates the pig's brain and kills it. The flat part, above and below the thread, served as a stop. This so that the screw thread only penetrates the brain as deeply as is absolutely necessary.

Lorenz Schlittenbauer ist unschuldig

The aim of hitting was not to crush the pig's skull. If the skull is struck too hard, the brain cannot be utilised as well (at the time, everything from the animal, including the brain, was eaten). So the weight of the blade had to be taken into account when striking with the screw thread. To do this, a hand was placed close to the blade (See the butcher's right hand in the symbolic picture above). Only in this way could the blow be delivered in a controlled and measured manner.


If an angry person were to strike with full force, there would not be much left of the victim's skull after one or two blows at the latest. Viktoria alone had 9 holes in her head, her mother 8 and the maid one.

Important: None of these skulls was smashed.


Only in Josef's case did the murderer strike with full force, as the blow was delivered through the sturdy pram roof.

The Circumstantial Mosaic

Clue No. 1: A.G. had a criminal record

A.G. had a criminal record for incest against his daughter Viktoria and served one year in prison.


Clue No.. 2: Irascibility

A.G. was known for his extremely aggressive and brutal treatment of his wife, children, and neighbours. 


Clue No. 3: Brutality

A.G. was quick to attack people with dangerous objects such as a scythe, pitchfork, or shotgun.


Clue No. 4: Child Abuse

Neighbours wanted to report A.G. for child abuse but refrained from doing so because they were concerned that doing so would only cause more suffering to the children. 

A.G. beat his children and often they did not even get anything to eat. He locked his children in the cold cellar for many days during winter. Sophie, one of his daughters, even died as a result of the abuse. 


Clue No. 5: Andreas Gruber announced the way of killing 

If Viktoria had been involved with other men without being pregnant by her father, Andreas Gruber would have beaten his daughter to death.

Statement by Viktoria Gabriel to Lorenz S.: "That's the better thing, that I'm pregnant by the father (Andreas Gruber), otherwise he would beat me to death". Translated: Viktoria was only allowed to meet with Karl G. and Lorenz S. because she was pregnant. 


Clue No. 6: The strangulation marks on Victoria's neck

The strangulation marks on Victoria's neck potentially indicate that there was an emotional bond between the perpetrator and the victim. 


Clue No. 7: Cilli Gabriel was a victim of desire, not killed for her money

The murderer could have killed Cilli with one blow. We can presume the murderer wanted to rape Cilli, since he did not kill her immediately. Cilli was scared to death. Her mother Viktoria and her grandmother Cäcilia were slain before her eyes and now it was her turn. Gruber still wanted to finish his plan to rape Cilli.

Gruber pounced on Cili and she panicked. She screamed like a banshee. Her tormentor took the iron band and hit the child's mouth with it to silence her. Cilli did not surrender, however, and tore her own hair out from her head in her death throes. Finally, Gruber cut the child's throat with his pocket knife, which he always had in his stable pant's pocket. The attempted rape explains why Cilli was found half-naked in the barn and why the child was not killed immediately.


Clue No. 8: The ingenious hiding place

Only an insider could know that there was a large enough cavity up above the kitchen in the false floor for the misshapen and at least 80cm long mattock.


This would be a completely illogical and in no way comprehensible action for an out-of-town murderer:

No out-of-town perpetrator hides murder weapons that do not belong to him (mattock, pocket knife, and iron band) in a foreign house with such considerable effort, high risk, and a lot of time involved; only to then make his escape.


Andreas Gruber did not destroy the murder weapon for the following reasons:

1. He was too cheap and miserly. He would not possibly destroy or throw away tools that were still usable. 

2. He was 100% convinced that no one would find the murder weapons...


Clue No. 9: The injury of Andreas Gruber

Andreas Gruber died from a fall on to the tip of the heavy pickaxe, which was found in the animal feeding trough on 04.04.1922. This tore open Andreas Gruber's carotid artery, causing him to bleed to death within a very short time. The flesh was torn open on the right side of his cheek and the cheekbone protruded. He only had this one injury, which was massively different from the others.


Someone who had intended to kill Andreas Gruber would have killed him in the same way as the other victims. Andreas Gruber, however, did not have a single hole in his skull. An outsider would also have struck Andreas Gruber several times to be quite sure that he could no longer be a danger to him. 


Clue No. 10: Habits - The tear-off calendar

According to the criminal investigation department, the crime was committed on the evening of 31st of March 1922. However, the tear-off calendar in the Hinterkaifeck kitchen showed the same date for the day on which the bodies were found, 1st of April, 1922.
Accordingly, one of the family must have still been alive on April 1st, i.e. one day after the crime. Tearing off the calendar days was a "sacred" ritual at that time and a habit that was always celebrated by the same person, usually the head of the family. 


No out-of-town murderer stays in the murder house after such a terrible deed, waits there for the next day, and then updates the calendar.

None other than the murderer himself has torn the sheet with the 31st of March from the tear-off calendar.


Clue No. 11:  The watchdog

The home security system of the time, the watchdog, was left alive by the murderer, as the dog was apparently still needed.

The watchdog, a yellow Spitz, was considered very alert in the neighbourhood. He would have alerted for every visitor and barked loudly. But since the danger came from within the house, there was no reason for the dog to sound the alarm. 

An out-of-town murderer would have killed the watchdog, as its yelping and barking would have attracted other people's attention.


An out-of-towner would never have attacked the family at this conspicuously bad time, since no one was in bed in the surrounding farms at that time.


Clue No. 12: The murderer stayed on the farm after the crime

A.G. was forced to stay on the farm because he did not know where to flee to.

If he had fled to his parents, they would have noticed immediately that something was wrong.
A.G. could not flee abroad either because he did not know his way around there. A.G. was therefore forced to stay in Hinterkaifeck.

He was trapped in his own house. 


In the process, the murderer demonstrably cared for the animals. 


The murderer did not sleep in his bed after the crime, but up in the hayloft, leaving haystacks behind. 

The murderer removed the roof tiles to keep a lookout for the police. Likewise, the murderer laid out a carpet of hay to muffle his footsteps so that no one would hear him if the police entered his house.


The killer attached ropes to various beams so that he could quickly lower himself to the ground should anyone enter the house/stable. The murderer even defecated in the hayloft because he did not want to leave his post (lookout).
Remains of rinds of smoked meat were found near the lookout. We can assume A.G. preferred the good smoked meat because he suspected that he would not get any more smoked meat for a long time.


No out-of-town offender would attach escape or reaction ropes, remove tiles from the roof, defecate in the hayloft and wait for the police to arrive before making his escape.


At the time, the criminal investigation department assumed that the escape ropes, the removed bricks etc. had already been placed before the night of the crime. However, this is not possible, because  it is known that Andreas G. had mentioned in a recent conversation that he  thoroughly searched the house, the stable and the hayloft in the night from 30.03.1922 to 31.03.1922, because he suspected riff-raff. He could not find anything conspicuous.

The two escape ropes tied tightly, the human excrement, the missing tiles in the roof, the rinds of smoked meat, the impressions left from someone laying in the hay and the hay carpet - all of this therefore only came to the hayloft after the night of the murder.  Strangers could not have hidden in the hayloft upstairs at all, because there was neither a serperate room nor a firewall up there. The upper floor was one big room where you could look over freely from one side to the other.


Clue No. 13: Gold and silver money were not stolen

At the time, the criminal police assumed a sixfold robbery-murder. However, large amounts of gold and silver money (approx. RM 100,000) were left behind.


The perpetrator preferred to go to great lengths to hide his murder weapons instead of looking for all the money...


The murderer who hid the mattock upstairs in the false floor knew the house inside out. So why didn't he steal all the money that was in the unlocked wardrobe in Viktoria's room? Because it wasn't the money he was after, but Cilli.


Clue No. 14: The bakehouse/washhouse

The murderer burned the bloody clothes (Cäcilia and Cilli's) in the bakehouse oven and cleaned his own with hot water. While doing so, he took the dog with him and tied it to the bakehouse so that the dog could warn him of neighbours or the police.

No out-of-towner would be so careless as to go to the trouble of burning the bloody clothes in the oven outside after this cruel deed.

The oven stood near the Feldstraße (field road), which people (such as Michael Plöckl) sometimes walked past. So the risk of being discovered by the smoke and the acrid stench would have been far too great. The effort to light the fire would also have been too great in this cold weather.  

(According to witness Michael Plöckl, the air stank of burnt rags on the evening of 01.04.1922).


The oven was usually always fired up on the same day (once a week) and at the same hour (early in the morning and not late in the evening) and was only used for baking bread as well as for heating the water (laundry).


Clue No. 15: Removing traces - covering the bodies

The murderer covered the bodies with hay and a door so that he would not have to look at them.

He tried to bury the bodies right next to where they lay. However, this was made difficult for him because the ground was frozen.

In a statement by Lorenz Schlittenbauer to the teacher Üblagger: He (L. Schlittenbauer literally said "he" (Andreas Gruber) so L. Schlittenbauer knew who he was talking about) dug a shovel-deep hole but "he" didn't get far because the ground was frozen...).


Clue No. 16: Andreas Gruber was not wanted as the successor on the parental farm

The parents did not sign over their farm to their eldest son Andreas, but gave it to Michael Gruber, his brother, who was three years younger.

Probable reason: Andreas Gruber could not handle people and animals.


Clue No. 17: Murder weapon: Andreas Gruber's pocket knife 

The pocket knife was a tool that Gruber always carried with him. Something always had to be cut with it (snacks in the field, cords, etc.). The knife also stayed in his trouser pocket overnight.

So how was an outsider supposed to get hold of the knife? The trousers with the knife inside hung in Andreas Gruber's bedroom.


Clue No. 18: Andreas Gruber wore his sleeping clothes on the day he was found

If he had heard anything suspicious in his bedroom, he would have got dressed. Gruber had to go through the kitchen to get to the stable, where the new maid could be since it was her first day.

It can be ruled out that Gruber went into the barn in his pants when it was snowing outside.

Andreas Gruber walked around in sleeping clothes one day after he had slain everyone, because he had to wash the blood splashes out of his only stable outfit (see indicator no. 14).

He hung the damp stable clothes up to dry in the living room and then holed up in the hayloft.


Clue No. 19: Overkill

The murderer struck Viktoria 9 times and his wife Cäcilia 8 times. This means that an "overkilling" took place. Andreas Gruber could not cope with the fact that his daughter wanted to leave him. He took out his hatred, frustration and anger on her and the others.

Exonerating facts for Lorenz Schlittenbauer

If Lorenz Schlittenbauer had been the murderer, he would not have hidden his mattock in the murder house and waited until it was found by the men demolishing it and handed over to the police.


If Lorenz Schlittenbauer had been the murderer, he would have had enough time after abandoning the Hinterkaifecker farm to retrieve the mattock, the pocket knife and the bloody iron band from their safe hiding place in order to destroy them.

But since only the murderer, who died shortly after the crime, could know where the mattock, the pocket knife, and the iron band were hidden, they remained in hiding until the farm was demolished (one year later).


The farm had been cleared for demolition and stood empty for some time. Lorenz Schlittenbauer did not even help to demolish the farm. This means that if he had been the murderer, he had to 100% expect that the neighbours would find his bloodstained, fingerprinted murder weapon(s) used to kill people.

(The mattock originally belonged to L. Schlittenbauer. He always left it covered in the field to continue working with it the next day. He did not want to carry it home with him every time. Andreas Gruber discovered the mattock and stole it).


Completely illogical and incomprehensible action of an out-of-town "insider": Nobody comes to a farm without a weapon in order to then kill 4 adults and 2 children with a tool that is foreign to him with a sophisticated beating technique, then hides the murder weapon(s) in a house that is foreign to him with considerable effort, high risk, and a lot of time involved, only to then make his escape. (See Clue no. 8)


When the bloody mattock was found during the demolition of the Hinterkaifecker farm, Lorenz Schlittenbauer immediately admitted in the presence of his neighbours that the tool they had found belonged to him.

Lorenz Schlittenbauer's original statement: "This is my mattock. I recognise it. So it was there in the yard all the time". By this he meant that his neighbours should finally realise that he could not have been the murderer, because at no time did he know where the murder weapon was hidden. If he had been the murderer, he would certainly not have hidden his mattock in the house where everyone was slain.


Lorenz Schlittenbauer's suspicion that Andreas Gruber had slain his family was confirmed when the main murder weapon was found in the ingenious hiding place.


The eyewitness Michael Plöckl testified that he had seen Lorenz Schlittenbauer with a battery-powered torch on the evening of 1st April 1922 at the bakehouse in Hinterkaifeck.

Schlittenbauer could therefore not have murdered the people, because they were demonstrably beaten to death on the evening of 31st of March 1922, i.e. one day earlier. No one returns one day later to the place where they had killed six people the day before.


In addition, Lorenz Schlittenbauer was unable to kill six people in a row because of his asthma. This was the conclusion reached by the authorities at the time.