Agnès Dupont de Ligonnès

The Dupont de Ligonnès murders and disappearance involved the murder of five members of the same family in Nantes, Loire-Atlantique, France, followed by the disappearance of the patriarch of the family, Xavier Pierre Marie Dupont de Ligonnès. His wife, Agnès Dupont de Ligonnès, and their four children, along with the family's two dogs, were killed at an undetermined date in early April 2011, and their bodies were found buried in their garden on 21 April. Xavier disappeared at the same time and has not been found. The exact nature of the events has never been determined, but Xavier is the subject of an international arrest warrant and is considered the prime suspect in the murders.

https://en.wikipedia.org/wiki/Dupont_de_Ligonn%C3%A8s_murders_and_d...