Until one month ago, the prolific true-crime author and documentarist Stéphane Bourgoin was France’s foremost expert on serial killers. Dressed in kitschy flowered shirts and flashy shoes, with a gift for dramatic rehashing and a glee for gore, Bourgoin was like the thirsty, gnomish love child of Jimmy Buffett and David S. Pumpkins.

With obsessive insight and purportedly intimate firsthand knowledge of famous criminals, but no actual degree or verifiable expertise, he has authored around 40 books, mostly in the true-crime genre, hosted conferences, pontificated on prestigious sound stages, and put his name to a series of comics on famous killers. He claimed to have interviewed 77 serial killers, among them Charles Manson. For years Bourgoin said he knew the identity of the killer of Elizabeth Short, better known as the Black Dahlia, whose 1947 murder gripped Hollywood for decades. The French public ate it up for more than three decades.

Cracking the Case

Then, starting last January, and really breaking this March, a group of anonymous amateur researchers who call themselves 4ème Oeil Corporation gave Bourgoin the fact-check of his life, revealing in a series of schlocky but impeccably documented YouTube videos that a sizable portion of his biography and books was either plagiarized or pure fantasy.

When Air Mail reached out, the group sent along a painstaking 122-page dossier addressing, one by one, a seemingly endless catalogue of lies: Bourgoin had said his own wife had been raped and murdered by a serial killer back in Los Angeles in 1976. (Nope. The victim was a woman he barely knew.) With the support of the police, he said, he had been given access to the victim’s dossier, and eventually to those of others unrelated to him personally. (Sure. Random French people with no credentials are always brought into the beating heart of open cases.) After Bourgoin recorded interviews with a number of serial killers, and offered them to the F.B.I.’s profiling division, they were so grateful that they offered him training. (Because the F.B.I. has time to train non-citizens, who can never become agents.) With this knowledge and experience, he taught behavioral science to France’s National Police for years. Mais non.

Bourgoin said his own wife had been raped and murdered by a serial killer back in Los Angeles in 1976.

Two decades of punditry, scores of authoritative books with legacy publishers, and almost no one bothered to confirm a single one of these easily disprovable facts except for eight meddling kids. Score another one for citizen journalism and what its practitioners sometimes call OSINT—open-source intelligence. Publicly accessible information just waiting to be noticed by someone who cares.

The key to Bourgoin’s success was that almost no one in his French-speaking audience knew any better, and they were the only ones he needed to convince. “Most French people are unable to speak and read English,” says “Maât,” one of the now seven anonymous researchers of 4ème Oeil. (A native Belgian who until recently worked as a tour guide in the French countryside, Maât named herself after the Egyptian goddess of justice. Of the original eight, “Sarah Connor” left the group after the videos went viral, feeling her work was done.)

Despite ongoing fascination with America⁠, where the serial-killer action really broke in the 1970s⁠, when Bourgoin was first burnishing his legend, in the late 1980s, there still wasn’t much homegrown expertise on the subject. “He said, Hey, no one would see the difference,” says Maât. “He never anticipated that the Internet would exist.”

The Fabulist Life

No area of Bourgoin’s life was unblemished by fabulism. He claimed his father was in the Resistance and was the first non-German, non-Russian to see the inside of Hitler’s bunker. He claimed to be a professional soccer player⁠—easily disproved. (Bourgoin later demurred that he was joking.) Bourgoin didn’t exactly go into the weeds for source material, either. He ripped off episodes from best-selling books by the prominent profilers John Douglas, the F.B.I. agent whose book Mindhunter: Inside the FBI’s Elite Serial Crime Unit was adapted by David Fincher into a TV series, and the South African Micki Pistorius, author of Catch Me a Killer: Serial Murders.

Bourgoin was an avid collector of correspondence from serial killers.

“Mr. Bourgoin made many claims which he copied directly from my autobiography, Catch Me a Killer,” Pistorius writes in an e-mail. “He was never part of any investigation in South Africa. He impersonated snapshots of my life, deceived the press, and charged the French public money to listen to his lies.”

“He made my personal experiences with violent criminals and my cases his,” writes Douglas in an e-mail. “I hope some entity in France doesn’t allow him to get away with this unpunished.” So far no one’s biting. “We want his comics removed from the shelves,” says Maât. The publisher of his true-crime books, Grasset, has announced that it is putting a forthcoming reissue on indefinite hold, but his comic-book publisher, Glénat, is refusing comment. No one has stepped forward with any kind of claim of damages.

The members of 4ème Oeil originally met up in a Facebook group dedicated to true crime. Some, though not all, of their own lives had been touched by violence, Maât says. With more women in the group than men, they decided to stay anonymous to avoid the wrath of Bourgoin-istes, and to erase any doubt that they were motivated by their own thirst for fame. “This (work) is solely out of respect for the victims and the families of victims,” Maât says. “This guy has been making money for 40 years off their suffering, preying on them like a vulture feeding on their sadness. This is unacceptable. We spoke to one of the surviving victims of [Michel Fourniret, “the Ogre of the Ardennes”], who said she was so shocked when she saw Bourgoin’s comic graphic novel on him it was like spitting in her face and killing all the others again.”

For more than a year the group split up their chores, compiling their videos, taking screenshots of their e-mail correspondence, and reaching out to journalists with a national profile, most of whom blew them off. “People like Jean-Marc Morandini and Jacques Pradel either didn’t answer or they said, You’re anonymous, why should I be interested?” Maât says. (Morandini changed course on May 18, dedicating a special edition of his half-hour afternoon show “Crimes et Faits Divers” to debunking Bourgoin.)

“This guy has been making money for 40 years off their suffering, preying on them like a vulture feeding on their sadness.”

It took Bourgoin himself for them to break through. “You know the Streisand effect?,” Maât asks. “It’s when you try to censor something and it becomes viral. Bourgoin saw our little videos and got really angry.” A claim was made for copyright infringement that succeeded in having the videos taken down. (Eight of them are now housed on 4emeoeilcorporation.me.; 4ème Oeil suspects Bourgoin was the author of the claim.) 4ème Oeil answered back on Facebook with a series of open letters, and finally journalists from the investigative site Arrêt sur Images and Paris Match got interested. Then came the cascade.

In the ensuing furor, Bourgoin has addressed the media briefly to apologize, blaming a lack of self-esteem for his lies, admitting he had documentation for only a dozen or so serial-killer interviews, but with every change in his story he keeps stepping deeper into piles. In explaining the shocking lie at the heart of his origin yarn, he said he lied about the victim’s identity—she wasn’t his wife but a barmaid and part-time prostitute—because he didn’t want people to think he paid for sex. “We checked” on the identity of the woman he finally named, Maât says, and could find no concrete proof she was a prostitute, though she was a real victim. “He picked her because her parents were dead and no one could contradict him.” (Air Mail repeatedly reached out to Bourgoin to address these claims and never heard back.)

After an interview with Le Parisien in which he bemoaned the lie he lived, Bourgoin has more or less stopped communicating except to his now private Facebook group of 2,500 members and his 12,200 followers on Instagram, where, among gardening and cat pics, he’s started to answer back with snapshots of his parents and newspaper articles. They don’t really reveal anything except their names, but they manage to serve as fodder for a lot of arguments in the comments. Half denounce Bourgoin’s lies. Others shrug, say they like his work, and ask when the next book is coming out. And there are a lot of colored hearts, left by fans who still like his cats. Nice work, Internet.

Alexandra Marshall is a Writer at Large for Air Mail based in Paris