The Dupont de Ligonnès Family Were Beloved Members of the Community

The sad, mysterious case is detailed in Netflix's Unsolved Mysteries.

france, nantes april 26, 2011 several hundred people take part in a march in nantes, western france, in memory of the five dupont de ligonnes members from the same family murdered in their nantes family house the bodies of the mother agnes dupont de ligonnes and her four children arthur, thomas, anne and benoit aged 13 to 20 years have been found in the garden of their house on april 21, 2011 the father, xavier dupont de ligonnes, is the prime suspect of the quintuple murder but it is not found yet the event started from the city center of nantes to reach the house of the tragedy flowers, candles and photos of children were placed before the house picture of the four children arthur, thomas, anne and benoit photo by alain denantesgamma rapho via getty images
(Image credit: Alain DENANTES)

Content warning: This article contains references to violence and murder, and one brief reference to suicide. In one of the most compelling episodes of Netflix's new Unsolved Mysteries, (opens in new tab) French investigators and friends retell the strange, tragic, and ultimately baffling story of the Dupont de Ligonnès family murders (opens in new tab). The seemingly perfect family—stemming from nobility, staunchly Catholic, involved members of the community, and filled with personality—apparently had deep secrets that were only revealed after every member of the family except one was methodically executed in their sleep and buried underneath the house. Four members of the family (Agnès, Arthur, Anne, Benoît) were killed sometime between April 3 and April 5, and the fifth family member (Thomas) was killed a short time after the rest.

Friends and family were concerned by their sudden disappearance, and asked the police to visit the house several times before the bodies were found—the investigation muddied by the fact that the patriarch, Xavier, who was missing, had written long and rambling letters explaining their disappearances and telling family members not to worry. Xavier became the main suspect in the family's murder, and has never been found, alive or dead. After the tragedy become national news, the family's money troubles came to light, as well as reports of marital tension between Xavier and Agnes.

Agnès Dupont de Ligonnès

The matriarch of the family worked at a Catholic school and was personable, according to neighbors. She also was, according to comments she apparently made anonymously on a French medical website (opens in new tab), unhappy in her marriage and worried about money troubles.

"I am lacking in everything: tenderness, love, mutual friends, sex, everything..." she wrote. "I have a husband who is very old-fashioned in his way of being in the family: the father is the head, he gives an order, we execute it without seeing to question or understand, period!"

Some neighbors insisted they saw Agnès after the date of her theorized death, but that's never been proven.

Arthur Dupont de Ligonnès

The oldest of the four children was not Xavier's biological son: Xavier and Agnès dated, broke up, then reconnected when she was pregnant by another man. Xavier took on the child as his own, including giving Thomas his name (according to a friend who spears in the episode, this would have been quite unusual in Xavier's conservative circles). Arthur was 20 when he died, and was pursuing a degree at a private Catholic college. Seen in the below photo goofing off by lying across his other family members (Benoît, Anne, Thomas), Arthur apparently had a girlfriend who became concerned when she stopped hearing from him, and a job that he stopped showing up for.

dupont de ligonnes family

(Image credit: Alain DENANTES)

Thomas Dupont de Ligonnès

Thomas, 18, was Xavier's oldest biological son, apparently shy and sweet, with an obsessive interest in music. Accounts differ as to when he was killed and why it was later than the rest of the family. The Unsolved episode notes that Thomas was visiting friends and was called home under Xavier's pretense that Agnes had been in an accident.

When Xavier and Thomas went out to a local restaurant for dinner on the night of April 4—when the rest of the family was likely already dead—the two barely spoke to each other, according to French media reports, and Thomas apparently said he wasn't feeling well. 

Anne Dupont de Ligonnès

Anne, 16, the only girl of the four, was a model for mail order catalogues. She was also the most studious of the four children and attended a Catholic school called La Perverie.

anne dupont de ligonnes

(Image credit: AFP)

Benoît Dupont de Ligonnès

Benoît, 13, attended the same school as Anne. Like his older brother Thomas, he was also apparently obsessed with music, in his case playing the drums.

A picture showing Benoit Dupont de Ligonnes

(Image credit: AFP)

Count Xavier Dupont de Ligonnès

Descended from nobility and the recipient of a count title after his father passed away, Xavier purported to be a businessman, but had limited success. When his father passed away, Xavier apparently learned that there was no family money left, but also inherited the same kind of rifle that would be used on his family. In the weeks leading up to the killings, Xavier reportedly learned how to use the gun and purchased cement and quicklime, later found atop the bodies. He wrote a note to family and friends saying he and the family were in witness protection with the Drug Enforcement Administration in the U.S. Then he disappeared.

Here's the big question. There are two predominant theories (opens in new tab) about Xavier's death—that he killed himself after traveling to the south of France to revisit some of the places he'd lived growing up (he was spotted on security footage as he made the trek), or that he disappeared from sight and fled to a different country. Although extensive searches were made, no body was ever found. Members of his family reportedly still do not believe he killed his own family, according to an old blog (opens in new tab).

xavier dupont de ligonnes

(Image credit: THOMAS COEX)

Someone purporting to be Xavier sent a note to a journalist (opens in new tab) in 2015, and there have been numerous sightings of him ever since—although police have never been able to confirm that any of these sightings were ever genuine.

If you have information about the Dupont de Ligonnès family, visit

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Katherine J. Igoe

Katherine’s a Boston-based contributor at Marie Claire who covers fashion, culture, and lifestyle—from “Clueless” to Everlane to news about Lizzo. She’s been a freelancer for 11 years and has had roles with Cosmopolitan and Bustle, with bylines in Parents, Seventeen, and elsewhere. It’s “I go to dinner,” not “Her huge ego,” but she responds to both.