On 11 December 1987, Fourniret and Olivier drove in separate vehicles to
Auxerre. Seeing 17-year-old Isabelle Laville walking home from school, a girl the couple had seen a day or two earlier and were targeting, Olivier stopped to ask her to join her in the car and give her directions, which Laville agreed to do. Driving down the road, Olivier reached the spot where Fourniret was standing with his car, pretending it had broken down. After Olivier, as planned, pretended to offer him a lift, he got into her car. Fourniret choked Laville with a piece of rope before Olivier sedated her with
Rohypnol. The couple brought the girl to their home in
Saint-Cyr-les-Colons, where Fourniret raped and strangled her. They threw Laville's body down a disused well in
Bussy-en-Othe. Her remains were recovered from the well more than eighteen years later, on 11 July 2006. In March 1988, Fourniret was contacted by 30-year-old Farida Hammiche. She was the wife of Jean-Pierre Hellegouarch, an imprisoned bank robber with whom Fourniret had shared a cell prior to the latter's release in October 1987. She asked Fourniret to help her unearth a haul from a cemetery in
Fontenay-en-Parisis, which had been stolen by members of the
Gang des postiches. After Fourniret and Hammiche managed to retrieve the haul, which consisted of
gold ingots and coins, Hammiche gave Fourniret a share worth 500,000
francs for helping her dig it up and hiding it in her apartment in
Vitry-sur-Seine. On 12 April, aiming to steal Hammiche's share, Fourniret and Olivier lured Hammiche out of her home. They drove her to
Clairefontaine-en-Yvelines, where they strangled her and buried her body. The couple then broke into Hammiche's home and stole the haul. They used the money they made from it to buy a
château called the Château du Sautou in
Donchery. Hammiche's body was never found. In January 1989, Fourniret met 21-year-old Jeanne-Marie Desramault on the evening train to
Charleville-Mézières. The two conversed before arriving in Charleville, where Desramault was staying at a convent. Desramault met Fourniret and Olivier, who had assumed false identities, at the train station again on 18 March, and the couple invited Desramault to come to their house in
Floing, an offer she accepted, and Fourniret promised he would drive her home afterwards. After they got to Floing, Fourniret asked Desramault if she was a virgin, and she told him she was not and that she had a boyfriend. Enraged, he attacked her. She fought back as he attempted to rape her, and as she attempted to escape, the couple gagged her with adhesive bandages before Fourniret strangled her. Fourniret and Olivier drove to Donchery and buried Desramault's body in the garden of the Château du Sautou. Fourniret and Olivier married in July 1989. On the afternoon of 20 December, they drove across the Franco-Belgian border to
Saint-Servais,
Namur, with their one-year-old son. Fourniret saw 12-year-old Elisabeth Brichet walk to a friend's house, and waited outside for her until she left to walk the short distance home just before 7:00p.m. He asked her to give him directions to a doctor's surgery for his son. She agreed to do so, and the couple drove back to Floing with her. When Fourniret undressed the girl, he saw that she was
menstruating, so Olivier cleaned Brichet's genitals. The next day, the couple took Brichet to the château, where Fourniret strangled her after a failed attempt to suffocate her with a plastic bag. Her body was buried in the garden of the château, near to that of Jeanne-Marie Desramault. There were a number of reported sightings of Brichet, in Belgium and abroad, in the years following her disappearance, and a number of people were suspected by police of abducting her, including another serial killer,
Marc Dutroux. After Dutroux's arrest in 1996, Brichet's mother Marie-Noëlle Bouzet helped to organise the
White March in honour of Belgium's missing and murdered children. The remains of Brichet and Desramault were exhumed from the gardens of the Château du Sautou on 3 July 2004, after Fourniret and Olivier confessed to the killings. The final known murder Fourniret committed with Olivier's help took place on 21 November 1990 near France's western coast. The couple drove to a shopping centre in
Rezé after leaving court in
Nantes, where they had been convicted of burglary. They saw Natacha Danais, a 13-year-old local girl, walking through the car park towards her home, having been sent to fetch her mother's forgotten purse. The couple lured Danais into the van, asking her for directions. After driving to a secluded area near the coast, Fourniret stabbed Danais twice in the chest with a screwdriver and strangled her before leaving her body on the beach. Later investigation suggested that the girl's body was raped after the murder. Eight days later, Jean Groix, a neighbour of Danais's family, was arrested after a white van belonging to him matched the description of the van that Danais' sister had seen her get into from across the shopping centre's car park at the time she disappeared. Groix was found to be lodging suspected members of the
ETA in his home; police suspected that Danais had found out about this and that he killed her for that reason. Two months later, Groix committed suicide in his prison cell. He was reported to have been unable to bear the burden of having been accused of murder. The Fourniret family moved to Sart-Custinne,
Gedinne, Belgium, in the early 1990s. Fourniret admitted that he committed two more murders in France between 2000 and 2001, his first in nine-and-a-half-years. He drove alone across the Franco-Belgian border to Charleville-Mézières on 16 May 2000 and lured 18-year-old Céline Saison, who was on her way home from school, into his van in the late afternoon. Driving with her back to Belgium, he raped her before strangling her with a rope and dumping her body in a forest in Sugny,
Vresse-sur-Semois. Saison's skeletal remains were discovered there by mushroom pickers on 22 July 2000. On 5 May 2001, Fourniret drove back to Sedan and met Mananya Thumpong, a 13-year-old girl of Thai origin whom he had met and given a lift home a few weeks earlier, outside the local library. He invited her to come to his house and play with his son. Accepting this offer, Thumpong climbed into the van and was driven to Nollevaux,
Paliseul, where Fourniret strangled her. Thumpong's remains were found on 1 March 2002, having been devoured almost entirely by wild animals. ==Arrest, trial and imprisonment==