The true story behind Netflix’s newest crime drama was too bizarre for TV

Netflix’s true crime drama “The Serpent,” premiering Friday, may seem unbelievable — but the creators actually had to temper the bizarre real-life history of con man and serial killer Charles Sobhraj. Set in 1970s Bangkok, the series, which first aired on the BBC earlier this year, follows Dutch diplomat Herman Knippenberg (Billy Howle) as he investigates the disappearance of a pair of Dutch backpackers. His pursuit leads him to Sobhraj (Tahar Rahim) and his accomplices, including Marie-Andrée Leclerc (Jenna Coleman) and Ajay Chowdhury (Amesh Edireweera), who have been drugging, robbing and killing tourists on the so-called Hippie Trail.

“Real life is infuriating, because it doesn’t behave in the way stories do,” says writer and producer Richard Warlow, who began working on the series in 2013 alongside director Tom Shankland. He calls it a “fact-is-stranger-than-fiction-to-the-power-of-about-100 situation”: “[I had] to do what you always do when you’re researching stories, which is do some conflations, light a fire under certain things and also — and I’ve never experienced this before — pedal back on some of the strangeness.”

Coproducer Paul Testar, who joined the development process in 2014, was tasked with accumulating research to support the storytelling. He worked closely with Knippenberg, who gave the team access to his extensive files on Sobhraj, as well as with Sobhraj’s former neighbor Nadine Gires; his captive employee Dominique Renelleau (whose escape from Sobhraj is documented in the series); and Interpol’s Lt. Col. Sompol Suthimai. Knippenberg provided Leclerc’s diary, and journalist Julie Clarke, who cowrote “On the Trail of the Serpent” with her late husband, Richard Neville, gave the production hours of taped interviews with Sobhraj.

“I tried to track down every single person who features in the story, or their surviving relatives if they’re no longer alive,” says Testar. “Building that research to be as huge as possible so we could draw from it — so we could draw these tiny, fine details in the story that become really important and be truthful about them and make sure we’re telling it accurately.”

A few of the people involved were made into composite characters for dramatic effect, one completely fictional character was added, and timelines were condensed at points. (The show’s dialogue is imagined too.) But Testar says 80% to 90% of the series is accurate. “I don’t think any of it is historically untrue. It was more a case of leaving stuff out.”

Here Warlow and Testar discuss what’s fact and what’s fiction in “The Serpent.”

After 21 years in an Indian jail, Charles Sobhraj, a.k.a the Serpent, is escorted by police to a court in New Delhi, India, for a bail hearing in 1997.

(Saurabh Das / Associated Press)

The series is based on interviews with Sobhraj — just not by the producers

Neville and Clarke’s interviews with Sobhraj, conducted while the killer was in prison in India, were essential to the writing of “The Serpent,” especially since the production team didn’t want to involve Sobhraj directly. (Neville and Clarke’s book was originally released in 1979, which means the interviews took place shortly after the events of the series.)

“We chose not to speak to him,” Testar says. “Julie and her husband, Richard, spent hours and hours and hours in prison interviewing Sobhraj and taping them. Julie gave us access to those tapes, which meant we could hear Sobhraj’s account of that period without having to engage with him directly. It felt like the only use of engaging with Sobhraj directly was to see how he’d lie to you and to see how he’d try to pull the wool over you. We were able to listen to those tapes from a more objective standpoint.”

“He is constantly trying to monetize himself and his story, and we were adamant that we would never pay him,” Warlow adds. “And the other thing is, he’s a compulsive liar, so whatever he had to tell us wouldn’t have been true.”

Charles Sobhraj was a killer, by his own admission

Sobhraj, born in 1944 to a Vietnamese mother and Indian father, was a scam artist and a killer. He drugged and robbed tourists for money and their passports, which he refashioned to use himself. The first known killing, which Sobhraj committed alongside Chowdhury, took place in 1975. The victim was Teresa Knowlton, played in the Netflix series by Alice Englert. There were several other homicides around that time attributed to Sobhraj and Chowdhury, although “The Serpent” doesn’t portray all the deaths. The total number of Sobhraj’s victims remains unknown.

“He’s been convicted of two murders, and he’s the chief suspect in many others in Thailand,” Testar says. “Arrest warrants were issued for those murders, but he successfully managed to avoid returning to Thailand, so they expired. Much of what’s known about the murders is from the mouth of Sobhraj himself, from interviews he gave to Richard Neville. As with everything with Sobhraj, it’s difficult to verify where the truth ends and where the lies begin.”

“Some people say over 20, some people say 12,” Warlow adds. “It’s one of those mysteries.”

Not all the victims included in “The Serpent” show up under their real names, because of requests from surviving family members. Dutch students Henricus “Henk” Bintanja and his fiancée, Cornelia “Cocky” Hemker, went missing in 1976 after staying at Sobhraj’s Kanit House apartment in Bangkok, spurring Knippenberg’s investigation, but they appear in the show as Helena Dekker and Willem Bloem. Similarly, Sobhraj’s first wife and daughter have fictional names in “The Serpent” to protect their identities.

“Sobhraj has been very good about building a false narrative about the people he’s alleged to have killed,” Warlow says. “And that false narrative pretty much goes ‘They’re druggies, criminal scumbags, and you shouldn’t care about them.’ I think that’s why a lot of the families were so reluctant to get involved with the drama. It was crucially important that we spend time with them and see this, rather than let them be anonymous and reinforce what has been a false narrative already about them.”

He adds, “The only character who is entirely fictional is in the first episode, the British hippie backpacker Celia. That’s because Teresa Knowlton was a very important character in the sequence of events and her uncle York Knowlton has been very supportive of us with the show. I was very keen from the outset to see what Teresa was like, so we gave her a friend to spend time with while she was in Thailand.”

Some of the victims escaped Sobhraj’s clutches

The third episode of “The Serpent” depicts Sobhraj’s relationship with the young Frenchman Renelleau (Fabien Frankel). Sobhraj cons Renelleau into working for him by taking away his passport and drugging him to make Renelleau believe he has dysentery. Renelleau begins to suspect foul play when visitors to Kanit House start getting sick and disappearing, and he confides in Gires (Mathilde Warnier) and her husband, Remi (Grégoire Isvarine), who help him escape.

In reality, Gires helped three of Sobhraj’s captives flee Bangkok, not just Renelleau. “There were two other people in that apartment at the same time,” Testar says. “We were never able to contact them or track them down. There was a feeling that dramatically, they had the same thing happening to them as to Dominique, [and] it was better to give all of it to Dominique to get under his skin as a character.”

Chowdhury’s fate is left open-ended, which is factual. In the sixth episode, Sobhraj drives Chowdhury to a deserted strip of land and abandons him, although it’s unclear whether that actually happened. Chowdhury was last seen in 1976.

“We don’t know what happened to him,” Testar says. “There’s this rumor that’s been put out that Sobhraj had Ajay killed, which I think is absolutely not true. It’s a useful fact and it plays into the mythology of the story, but another associate of Sobhraj from Bangkok, a German guy, disproved it. After Sobhraj and Leclerc had been arrested in India, several months after he was in prison, this guy had a visit at his home in Germany and phone calls from Ajay. It would be pretty difficult for him to have been killed by Sobhraj when Sobhraj was already in prison. What happened to him is a complete mystery.”

Yes, Sobhraj really did keep a pet monkey

Many of the small details in “The Serpent” are based on interviews with Gires and Renelleau, who both lived in Kanit House. Viewers in the U.K. were horrified when a monkey is poisoned in Episode 3, for instance, but the creators based that on real events: Sobhraj and Leclerc’s pet monkey, Coco, got his hands on the medicine Sobhraj was using to debilitate Renelleau and dropped dead.

“The events that take place are so outlandish and then you find out that it actually happened,” Warlow says. “I got so many people saying to me ‘What, the monkey? Really? He drank the poison? Really?’ And yes, that was 100% as it happened.”

“That was something Dominique told us,” Testar adds. “He was so sad that he’d accidentally poisoned it. It sounded like a horrible life for the monkey. There was something we decided not to include, because it would just be too terrible, but apparently, the monkey was not house trained, so he wore diapers. That’s one of those extraordinary details that feels like ‘That’s too far. People won’t believe that.’”

Sobhraj got a life sentence after years of fame

Captured in New Delhi after he drugged the members of a student tour group, Sobhraj eventually went to prison in India, serving time from 1976 to 1997. After his release, he returned to Paris and lived as something of a celebrity. He gave several prominent interviews, including to an ABC news team, and at one point, director William Friedkin signed on to direct a movie about Sobhraj starring Benicio del Toro. Then, for some reason, Sobhraj returned to Nepal, where there was an outstanding warrant for his arrest in the killings of Laurent Carrière and Connie Jo Bronzich (played by Benjamin Braz and Dasha Nekrasova, respectively).

“I wouldn’t say he gave himself up, but he publicized his arrival,” Testar says. “He made it very clear that he was there. He went to the casinos and was photographed. But why is one of the great mysteries of the story, and it’s one we don’t try to explain.”

Sobhraj claimed that he returned to negotiate an arms deal between the Taliban and the CIA, but it’s been speculated that his hubris was so great that he thought the warrant had expired along with the one in Thailand. It’s also possible that he craved the spotlight at any cost. Whatever the reason, Sobhraj was arrested in Kathmandu on the day of Knippenberg’s retirement — a detail left out of the final episode.

“When Herman got the news that Sobhraj had been arrested in Nepal in 2003, he was having a [cocktail], because it was the first day of his retirement,” Warlow says. “From a dramatist[’s] point of view, that’s the sort of thing that if I wrote that I’d hate myself for it. It’s so on the nose. But really, what’s been the story of his life came calling for him on the day he’d given it all up.”

He adds, “Herman was the reason I wanted to do this. You’ve got two diametrically opposed men who were born within months of each other, who never met each other, but had this revolutionary effect on each other’s life. One was this mercurial ‘70s lizard king and the other one was a square, to use the vernacular of the time. I was very interested in the square bringing down the hip king. There’s a version of this show where you’re just watching Charles pulling incredibly evil s— time and again for hours. I never wanted to tell that story. I was always looking to see the process by which he was caught.”