Fredrik von Sydow came from an upper-class family in Stockholm and studied law at Uppsala University. On March 7, 1932, his father Hjalmar von Sydow - who was a conservative member of parliament and CEO and president of the Swedish Employers' Confederation - and two family maids were found dead in their residence in Stockholm, all beaten to death with an iron rod.

Although the police soon began to suspect the son, it took a few hours to locate him. Fredrik von Sydow had taken a taxi with his wife Sophie to Uppsala, where they entered the restaurant of the Gillet Hotel and ordered champagne, caviar, and oysters. When the police finally arrived at the scene, he had already shot and killed his wife and committed suicide.

The von Sydow murders received renewed attention in Sweden in 2004, as a result of the publication of Hensen's novel, whose mother was the youngest daughter of the family. The story is a blend of real events and fiction and is an attempt to understand both the taboo that arose in the family regarding the crime and the reason why Fredrik von Sydow committed the murders.