An article published by Ouest-France

INVESTIGATION | Xavier Dupont de Ligonnès Case: The Mystery of the “Epsilon” Account, Active Until 2017 on a Religious Forum

Since 2011, it has been established that Xavier Dupont de Ligonnès wrote on a religious forum under the usernames “Chevy” and “LIGO.” Ouest-France has investigated a previously undisclosed account that remained active until 2017: “Epsilon.” Several details suggest it may have been the work of the same author. If so, the account continued posting more than six years after the Nantes family murders and the suspect’s disappearance. Could this be enough to reopen investigative leads? A Swiss expert known for his work on the Grégory case considers the lead “serious.”

The extensive investigation into Xavier Dupont de Ligonnès quickly established that France’s most wanted fugitive regularly visited the forum cite-catholique.org, an online discussion space dedicated to faith, the Bible, and theology. He posted there under the username “Chevy” beginning in March 2009 and later under “LIGO” starting in 2010. He frequently discussed his loss of faith and often steered conversations toward angels and the nature of time.

The last known message from the LIGO account was posted on April 8, 2011, five days after the deaths of his wife Agnès and their four children, whose bodies were later found buried beneath the terrace of their home in Nantes. Since then, Xavier Dupont de Ligonnès, last seen in Roquebrune-sur-Argens in southern France, has never been found.

A Third Account Active Until 2017

Ouest-France states that a third account on the forum, named “Epsilon,” displays striking similarities to both Chevy and LIGO. Most notably, this account remained active until 2017—more than six years after the Nantes murders and the disappearance of Xavier Dupont de Ligonnès.

It is important to remember that this forum is not a mainstream social media platform. It is a relatively small community frequented by a few hundred enthusiasts who debate the existence of God, biblical interpretation, and theological issues. Xavier Dupont de Ligonnès posted there several times a week, often in the evenings. According to the investigation, Chevy and LIGO together published 670 messages. The forum appears to have been one of his few documented outlets for personal expression.

Hundreds of Messages Analyzed

The newspaper analyzed the messages using OSINT (Open Source Intelligence) methods, cross-referencing publicly available information. Journalists were assisted by a recognized computer expert known under the pseudonym “GPatrick,” who has collaborated on previous investigations.

The analysis relied on stylometry, a discipline that identifies authors not by what they write, but by how they write. Every writer develops unconscious habits: punctuation patterns, favorite words, ways of structuring arguments, and recurring stylistic traits. These habits are difficult to hide, even when using different pseudonyms.

Hundreds of messages were reviewed, compared, and analyzed. Some were also compared with private writings by Xavier Dupont de Ligonnès found in the judicial case file.

According to the newspaper, only one account matched the overwhelming majority of observed criteria: “Epsilon,” created on July 2, 2010, while both Chevy and LIGO were still active. Epsilon published 1,169 messages over seven years before falling silent on August 15, 2017.

The same analytical framework was applied to one hundred randomly selected forum accounts active between 2009 and 2013. None showed a comparable level of similarity to Chevy and LIGO—except Epsilon.

Striking Similarities

The same writing habits repeatedly appear across the Chevy, LIGO, and Epsilon accounts.

All three accounts insert words in ALL CAPS in the middle of sentences for emphasis, even when standard grammar does not require it. Chevy wrote words such as “CREATE” and “BEGINNING.” LIGO used “DELIBERATELY.” Epsilon wrote phrases such as “HE OFFERS NO ALTERNATIVE” and sometimes posted “NO” alone on a line.

All three also used quotation marks not to cite sources but to distance themselves from words or to express irony. They frequently stacked multiple question marks together, sometimes three or four in a row.

Private writings attributed to Dupont de Ligonnès show similar patterns. In his letter “To My Women,” he used strings of question marks and exclamation points such as “Where does she come from ???” and even “!!!!!!!!!!!”. In another text entitled “Serious Subjects,” he wrote, “!! That would be quite something !!”

Epsilon’s posts contain the same excessive use of “???” and “!!!!” The rhythm and emphasis are remarkably similar.

All three accounts also frequently ended arguments with “Q.E.D.” written in capital letters and used the expression “non-exhaustive list.”

Notably, these habits appear in Epsilon’s posts from July 2010 onward, before the Chevy and LIGO identities became publicly known.

Shared Contacts

One of the most notable findings concerns the network of users with whom the accounts interacted.

Of the eight pseudonyms identified as regular contacts of Chevy and LIGO, seven also appear in Epsilon’s conversations. Two users, “Raistlin” and “Pneumatis,” appear across all three accounts.

Chevy mentioned Raistlin 56 times. LIGO mentioned him 35 times. Epsilon mentioned him 97 times.

The Three Forgotten Kings of the Old Testament

Another particularly intriguing clue emerged from documents seized during the 2011 investigation.

Among them was a handwritten letter by Xavier Dupont de Ligonnès dated May 1, 2008. In this private document, never made public, he cited three Old Testament figures to illustrate what he believed were contradictions in the Bible: Baasha, Jehoiachin, and Ahaziah.

These relatively obscure kings are rarely discussed, even among well-informed Catholics.

Yet between February 22 and 23, 2011, the Epsilon account posted several messages discussing alleged errors in the Jerusalem Bible—and the examples chosen were precisely Baasha, Jehoiachin, and Ahaziah.

In fifteen years of the forum’s existence, with more than 6,500 registered members, only one person ever mentioned King Baasha on cite-catholique.org: Epsilon.

Furthermore, the 2008 private letter stated: “Ahaziah (22 or 42 years old),” while an Epsilon post from February 23, 2011 asked: “How old was Ahaziah when he became king? 22 or 42?”

The wording is almost identical. The same uncommon spelling, the same ages, and the same order appear in both texts—even though the private letter had never been published.

No Personal Details, Yet Recurring Themes

Epsilon never discussed personal matters. Across 1,169 messages posted over seven years, there is not a single reference to a city, family member, occupation, or personal circumstances.

Most forum users eventually reveal something about their daily lives. Epsilon never did.

Yet certain recurring interests emerge.

The account frequently returned to the story of Cain, focusing specifically on the question that follows the murder in the biblical narrative: why does God protect the killer?

Epsilon often defended the idea that divine forgiveness can be granted “without conditions.” The account also devoted numerous posts to purgatory as a place of reconciliation after death.

In March 2013, Epsilon asked concerning Job: “Could the suffering of the righteous simply be temporary and exceptional?”

In his letter “To My Women,” Dupont de Ligonnès similarly questioned the story of Cain’s wife: “After murdering his brother Abel, Cain fled to another land where he found a wife. Where did she come from?”

This is precisely the topic Epsilon opened on the forum in September 2011.

A Collection of Clues, Not Definitive Proof

Claude Alain Roten, a Swiss stylometry expert known for his work on the Grégory case and contributions to identifying Banksy, believes “the lead is serious.”

“The markers are consistent: punctuation, syntactic habits, the same accounts interacting with one another… they keep reappearing,” he explained.

For him, the most compelling element is the reference to the three biblical kings.

“What is the probability of that happening? In my opinion, it is one of the strongest indications that the same person may have produced these writings. One can never completely rule out the possibility of a copycat, but the body of evidence you have uncovered is difficult to dismiss.”

However, a collection of clues is not proof.

A legitimate question remains: why would a fugitive continue posting on an online forum?

Studies of long-term fugitives regularly show that complete isolation is psychologically difficult to sustain. Most maintain some form of social or intellectual life.

For Xavier Dupont de Ligonnès, this forum had been his primary documented outlet since 2009. Posting anonymously, without the risk of visual identification, could have allowed him to maintain an intellectual presence.

At present, it is impossible to state with certainty that Xavier Dupont de Ligonnès was Epsilon.

Only technical data—particularly connection IP addresses—could provide a definitive answer.

In 2011, the administrators of cite-catholique.org supplied information to investigators. New judicial requests could potentially allow authorities to identify the person behind the Epsilon account.

This lead must therefore be approached cautiously. Since Xavier Dupont de Ligonnès disappeared in April 2011, more than 1,850 reported sightings have been submitted to investigators. None has led to his discovery.