Xavier Dupont de Ligonnès: A cop at the heart of the case (Expanded and Updated Edition)

An updated and expanded edition of a book published in February 2026. 
20,000 copies printed

What if the Dupont de Ligonnès case were reopened thanks to Gilles Galloux? The investigator from the Central Cybercrime Office of the Judicial Police, who was in charge of the digital manhunt for Xavier Dupont de Ligonnès in 2011, is diving back into the case that turned his life upside down a decade later.

For the past two years, Gilles Galloux has been revisiting neglected leads, tracking down forgotten witnesses, and uncovering details never before revealed to the public. He sheds light on specific movements in Saint-Nazaire, crucial gaps in the days leading up to the tragedy, and data that had never been linked together. Through investigations conducted in the Var and the Nantes region, he pieces together facts that reveal methodical planning and trace the direction taken by the fugitive after his disappearance on April 15, 2011.

This rigorous work offers a structured reexamination of a case that has become a national legend. A personal, unprecedented, and indispensable investigation for understanding one of the most significant criminal cases of the past fifteen years.

Gilles Galloux was an investigator with the Central Office for the Fight Against Crime Related to Information and Communication Technologies (OCLCTIC), which is the Cybercrime Unit of the Judicial Police. He was assigned to the case on April 29, 2011, when the Nantes Judicial Police requested an urgent digital forensic analysis of Xavier Dupont de Ligonnès’s online activities. He was tasked with analyzing Xavier’s pseudonyms, usernames, connections, and activities on religious forums, particularly Cité-Catholique; linking IP addresses, logs, and digital traces to Xavier’s movements; working with data from telephone operators; securing court orders regarding digital leads; and coordinating the “digital manhunt.” Now retired, Gilles Galloux continues his research and is assisting Canal+ in the preparation of a new series dedicated to the case.