PARIS—A man kidnapped a 16-year-old girl at knifepoint in 1998 from the streets of La Rochelle, a port city in western France. He drove her to a wooded area and raped her, leaving her traumatized but alive.
Over the next decade, four other girls and young women were sexually assaulted in similar settings by a man described by victims as tall and gaunt with piercing light-colored eyes. DNA samples confirmed it was the same attacker, who became known as the Predator of the Woods.
Police plugged the suspect’s DNA data into law-enforcement databases in France and sent it to all 194 member nations of Interpol but found no match, according to police and judicial records of the case. Authorities interviewed hundreds of people, distributed sketches of the assailant and tested the DNA of men deemed to resemble the sketch. No suspect was found.
Nearly two decades after the first known assault, an elite unit of the French national police took over the case. The unit specializes in cold cases and serial crimes, solving puzzles that prove too tough for rank-and-file officers.
The lead investigator pursuing the Predator of the Woods has the by-the-book demeanor of a high-school principal, a law degree and decades steeped in rape and murder cases. She asked, because of the nature of her work, for the courtesy of anonymity.
In 2018, she and her team learned of a new technique used by U.S. investigators called genetic genealogy: Agents of the Federal Bureau of Investigation submitted crime-scene DNA samples of unidentified perpetrators to commercial databases holding millions of genetic tests from people curious about their origins and family ties. The agents and local police found relatives of suspects and, often, the suspects themselves by mapping family trees.
For the French investigators, it would be a long shot. Recreational DNA testing is illegal in France, so its citizens account for a small percentage of entries in the main databases used by U.S. law enforcement, GEDmatch and Family Tree DNA. Plus, a person’s identifying DNA is subject to Europe’s strict data-privacy rules. A prosecution based on genetic information collected illegally might not hold up in court.
Yet the threat of more attacks—and the lingering anguish of victims and their families—weighed heavily against the laws that have kept DNA data in Europe under strict lock and key.
“There’s a very, very strong expectation from society that will no longer tolerate the fact that we have the technical means to solve crimes, but then refuse to do it,” said Fares Aidel Sehili, a lawyer who represented a victim of the Predator of the Woods.
The French investigators decided to test legal boundaries to catch the Predator of the Woods and called the FBI for help, said Charlotte Sawicki, deputy director of the OCRVP, a division of the national police that oversaw the investigation, and the lead investigator’s boss. They sent a DNA sample of their suspect to the FBI and waited.
“We were stepping into the unknown,” Sawicki said.
Carbon copy
The hunt for the Predator of the Woods took shape in the offices of the OCRVP, a clunky French initialism for the Central Office for the Repression of Violence Against People. The office, based in Nanterre, a drab suburb of Paris, handles difficult investigations that span murders, kidnappings, sexual assaults, disappearances and unsolved serial crimes.
To get around the legal difficulties of using genetic genealogy, the French investigators in 2021 asked the FBI to search commercial databases for them. “Legally speaking, it would have been too risky” for the French officers to do the work themselves, Sawicki said.
Meanwhile, investigators recirculated sketches of the suspect, asked the public for help and sifted through a mountain of tips.
The Predator of the Woods was one of France’s most perplexing cold cases. His first victim was in La Rochelle. Four others were attacked around 250 miles away, in the Paris region. The man had raped four victims from 1998 through 2000. The fifth assault was in 2008—the victim, a woman from the 13th district of Paris.
The assaults followed a pattern, the lead investigator said, “almost carbon copies.” The man identified his victims as they walked on city streets. Some he persuaded to get in his car, a Peugeot in the first crimes and, later, a Renault. He took others by force. In the car, he talked about sex with his victims, then drove to isolated, wooded areas where he raped them.
Investigators fed those details into software developed by the Royal Canadian Mounted Police to identify and sort patterns of violent criminals, seeking to surface any other, unreported assaults by the Predator of the Woods. They came up empty-handed.
Six months later, in 2022, the FBI passed on a lead. Matthieu Bouvet, a genealogy enthusiast and professional archivist living in Brittany, France, had defied the national prohibition on recreational DNA testing and uploaded the results to Family Tree DNA.
The FBI said Bouvet turned out to be a distant relative of the Predator of the Woods. “A happy coincidence,” Bouvet said. France’s ban on recreational DNA testing was stupid, he said: “To manage the risks, we should authorize it—perhaps with limits—but allow it nonetheless.”
The French police were elated by the lead from Bouvet’s profile, but they soon learned how much more work was ahead. Bouvet’s ancestors were members of large French families. Some of his great-great-grandparents had as many as 11 children. The number of descendants to check would be in the hundreds, maybe even the thousands.
Private matter
Sweden became the first European country to crack a cold case using genetic genealogy in 2020, when authorities solved a double murder from 2004. The country legalized the method last year, in a law reserving its use when absolutely necessary to solve the most serious crimes.
Law enforcement and victims’ families across Europe are now pushing for broad legalization. In Spain, the Netherlands and Denmark, police agencies have already used the technique or are preparing to do so.
The government of President Emmanuel Macron in France is backing legislation that would legalize genetic genealogy for police use.
“A magistrate who accepts judicial cooperation with the United States on this matter is liable to prosecution,” Gérald Darmanin, the French minister of justice, said in the legislature this month. ”We are simply asking for the criminalization of the judge to be lifted.”
Lawmakers on the French left oppose the legislation, as does France’s National Consultative Commission on Human Rights, a government body.
“Individuals who consented to recreational testing did not necessarily consent to the use of their data for law enforcement purposes—let alone individuals who did not undergo testing but share genes with those who did,” the commission said in an opinion to the French legislature.
While recreational DNA testing in the U.S. has few legal limits, European privacy laws sharply restrict buying, selling and sharing personal data, including DNA. There are widespread concerns that law-enforcement officials are exploiting the data stored in U.S. commercial databases without proper consent from users. GEDmatch and Family Tree DNA ask users whether they want to be included in law-enforcement searches.
In the U.K., police are barred from accessing the U.S. DNA databases. One cold case they hope genetic genealogy can crack is the killing of Janet Brown, a nurse bludgeoned to death at her home in Buckinghamshire 31 years ago.
The Thames Valley Police said they hadn’t found a match for a DNA profile believed to belong to the suspect from law-enforcement databases in the U.K. and some 25 other countries. They want permission to plug the DNA into GEDmatch and Family Tree DNA.
“Hopefully, we will get the go-ahead from the Home Office to use this technique in the near future, but I have been waiting for quite a while now,” said Peter Beirne, a senior investigator with the Thames Valley Police. He said the department has four unsolved cases that could be cracked using DNA databases in the U.S.
London’s Metropolitan Police is running a pilot program on genetic genealogy to see whether it could be used in the U.K., a Home Office spokeswoman said.
Data crunch
Investigators in the Predator of the Woods case began mapping Bouvet’s distant relations with the help of a family tree Bouvet posted on Geneanet, a genealogical website. Geneanet sent the police the names of Bouvet’s 16 great-great-grandparents, born in the mid-19th century.
Bouvet started his research some 15 years ago, sketching out a family tree that numbered more than 6,000 people.
Investigators fused data from Bouvet’s research with records from France’s national identity databases and local archives from towns nationwide. As they worked down from those 16 great-great-grandparents, they noted men who fit the description given by victims—those 6 feet or taller, now in their 50s and 60s, with blue or green eyes.
Several months later, investigators got another break. The FBI reported a second match between the Predator of the Woods suspect and a French man born in 1960. The FBI had their names and asked French authorities to provide more information about their ancestors and siblings.
Three months later, the FBI narrowed the family tree even further, telling the French investigators to examine the descendants of a woman born in Belfort in 1902 and a man born in Besançon in 1901, which marked the junction between Bouvet’s family tree and that of the man born in 1960. This couple had five children.
The French police pulled up identity cards of the male grandchildren, looking for the right age, height and light-colored eyes. One of them, a 62-year-old named Bruno Llambrich Gonzalvo, bore a resemblance to the sketch of the Predator of the Woods drawn from descriptions by victims.
At 5:30 a.m. on Dec. 13, 2022, police raided a house in Courtry, a northeastern suburb of Paris where Llambrich Gonzalvo was living with his girlfriend. They detained him, immediately took a DNA sample and sent it for testing.
One of six children, Llambrich Gonzalvo had grown up in a housing project outside Paris. He spent most of his life bouncing from job to job—including as a counselor at several French summer camps. He had been convicted of a sexual assault in the 1980s against a woman he had picked up hitchhiking, but the conviction was expunged from his record.
Later that day, the laboratory said his DNA was a match for the Predator of the Woods. He confessed in police custody.
“I was asking myself when I would be arrested,” he later told a French magistrate, according to case files. “I deserved it, I thought often about all the wrong that I’ve done.”
Llambrich Gonzalvo was HIV positive. He said he contracted the virus in the 1980s and knew he was infected when he raped his first victim in 1998 in La Rochelle. He said he couldn’t remember why he was in La Rochelle, according to the files.
As the years passed, he made no apparent effort to hide: He appeared on a candidates list in local elections for Courtry in 2020. His candidate photo was on his party’s Facebook page months after the police began recirculating the sketch of the Predator of the Woods.
Llambrich Gonzalvo would never be tried for the crimes. In March 2024, he died by suicide in his cell at a prison outside Paris.
‘Haunts me’
On the night of Jan. 10, 1990, Cornelia Pfau and her boyfriend walked out of a bar in Freiburg, a picturesque town in the Black Forest region of southwest Germany. Her boyfriend went back inside the bar for a few minutes. When he returned, he and another witness would later recall, Cornelia was getting into another car, driven by someone she seemed to know.
The next morning, two joggers found her body at the edge of a forest a few miles away. She had been raped and strangled, and investigators recovered semen from her body. Cornelia’s daughter Natascha, who was 6 years old at the time, was staying at her grandparents’ house nearby.
German police tested the DNA from the semen against a few people, including Cornelia’s boyfriend and Natascha’s biological father, without a match. A special investigative team was disbanded after a few months.
Years later, Natascha Pfau began to lobby authorities in Baden-Württemberg, the German state where Freiburg is located, to try again to find her mother’s murderer.
“It haunts me whether he might still be living nearby, whether I know him, and whether I might even have contact with him today,” Pfau said.
The case also drew the attention of Karsten Bettels, a retired German police officer who investigates cold cases. He pressed for a new investigation and believes genetic genealogy should be used to find the killer of Pfau’s mother. But authorities say the technique violates German constitutional rights to privacy.
“It is vital to also consider the perspective of the families left behind,” said Pfau, “who have to live for years with the agonizing uncertainty of what happened to their loved ones.”
Bettels noted that Cornelia Pfau’s body was found just a few miles from the border with France, where authorities caught the Predator of the Woods using DNA databases in the U.S.
“It was not her fault that she wasn’t found on the French side,” he said
Write to Matthew Dalton at Matthew.Dalton@wsj.com
