Hinterkaifeck murders

On the evening of 31 March 1922, six inhabitants of the small Bavarian farmstead known as Hinterkaifeck, located roughly 70 kilometres north of Munich, were killed by an unidentified perpetrator. The victims were farm owner Andreas Gruber (63), his wife Cäzilia (72), their widowed daughter Viktoria Gabriel (35), her children Cäzilia (7) and Josef (2), and the family's newly hired maid, Maria Baumgartner (44), who had arrived at the farm only the day before. All six were killed with a mattock, a farm tool later recovered hidden in the barn's loft. Evidence indicated that Viktoria, her daughter, and her parents were lured into the barn and killed there first, followed by the murders of Josef and Maria inside the farmhouse.

In the months preceding the killings, the household reported unexplained events, including noises in the attic that had prompted a previous maid to quit, an unclaimed newspaper found on the property, and footprints in the snow leading to a farm building with a broken lock. These reports were not made to police at the time.

The bodies were not discovered until 4 April 1922, four days after the killings, when neighbour Lorenz Schlittenbauer and others entered the farm after repeated failed visits by tradesmen and a mechanic, and after the family's absence from school and church had been noticed. Investigators determined that the perpetrator had remained on the property for several days afterward, feeding the livestock, using the fireplace, and consuming food from the house.

An investigation led by Munich inspector Georg Reingruber was hampered by contamination of the crime scene, as numerous onlookers had already moved bodies and evidence and even prepared meals in the farmhouse kitchen. An initial theory of robbery as a motive was dropped after money was found undisturbed in the house. Numerous individuals were investigated as suspects over the following decades, including Viktoria's husband Karl Gabriel (reported killed in World War I but whose body was never recovered), neighbour Lorenz Schlittenbauer (who had a prior relationship with Viktoria and behaved suspiciously at the scene), members of the Freikorps Oberland paramilitary group, and several local men named by a former maid, Kreszenz Rieger, and other witnesses. None of these individuals were ever convicted, and the case was formally closed by authorities in 1955, with final interrogations occurring as late as 1986.

The case has since become one of the most widely discussed unsolved crimes in German history. It has inspired documentaries, plays, radio broadcasts, and a best-selling fictionalized novel, and was reexamined in 2007 by police academy students using modern investigative methods, though the perpetrator's identity was never conclusively established.