Arthur Nicolas 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.

Arthur Nicolas Dupont de Ligonnès was born on 7 July 1990 to another father, but was recognised by Xavier as being his son when he married Agnès when Arthur was two years old.[15] He earned a baccalauréat in Science, Industrial Technology and Sustainable Development at the age of 20.[16] He was studying for a technical diploma in IT at the Saint-Gabriel private college in Saint-Laurent-sur-Sèvre in the Vendée department, an hour's drive from Nantes.[17] He was also employed as a waiter at a pizzeria in Nantes. He was 20 years old at the time of his death.

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