Henderson’s writings and social media posts also referenced “groomers” and “handlers.” Among the half-dozen nicknames Henderson dropped, one has been flagged for its association with three separate deadly attacks.
“Nitro groomed me,” Henderson wrote on his Bluesky account one day before he took a gun to school and killed a 16-year-old student. And in a diary that he left behind, Henderson mentioned Nitro, also known as “Nitrogen,” as being among his “top ‘groomers.’”
Henderson’s writings brim with dehumanizing tropes and grotesque descriptions of violence, suggesting, at least in part, that the purpose of his propaganda was to shock and alarm parents, teachers and other authority figures.
Carla Hill, director of investigative research for the Anti-Defamation League’s Center on Extremism, told Raw Story in an email that Henderson’s post “may have been a trolling effort” or “perhaps an inside joke.” She added: “We have no evidence that Nitro played a direct role in guiding or mentoring Henderson. What is more likely and perhaps notable is that Henderson had to have been in online spaces either with Nitro or where he was discussed, because he was familiar with him and versed in his activities/reputation perhaps.”
While the exact role played by the “groomers” and “handlers” cited by Henderson remains unclear, the nicknames and social media accounts are likely to provide investigators with leads on a potential network of operators — part of a global network — who may be working behind the scenes to instigate terrorism.
“They think we’re satanic pdf groomers. Part of super Mkultra cult making kids kill,” Henderson wrote in an X post that tagged Nitro in mid-December last year, referring to a CIA mind-control experiment. “They [sic] people are f---ing stretching. I’m just trolling; I barely know her.”
Henderson was talking about Natalie Rupnow, a 15-year-old who fatally shot a fellow student and teacher at Abundant Life Christian School in Madison, WI before taking her own life. Rupnow’s attack turned out to be eerily similar to the one Henderson himself would carry out about a month later.
But privately, according to a diary entry from the same period, Henderson suggested he was much more closely connected to Rupnow.
Henderson took note of an X post by Rupnow shortly before she carried out her attack. In the post, Rupnow displayed a photo of herself making a hand sign. Henderson wrote in his diary that he recognized the gesture as the “white power symbol” used by Brenton Tarrant, the white supremacist who slaughtered 51 Muslims in an attack on two mosques in Christchurch, New Zealand in 2019.
Rupnow followed the photo with a post linking to a Google Docs version of her manifesto, although she neglected to make it public.
“Livestream it,” Henderson wrote in reply.
Later, he expressed excitement in his diary that Rupnow had followed two of his X accounts.
For his part, the person who goes by the name Nitro admitted to being in an online voice chat with Rupnow, and, according to the Center on Extremism, distributed a hoax version of her manifesto on X.
Nitro’s identity remains unknown, but based on an apparent recording of his voice reviewed by Raw Story, he appears to have an English accent and confirmed in the recording that he was in the time zone for the United Kingdom. An X post uncovered by the Center on Extremism indicates Nitro is 17 years old — the same age as Henderson was — and that he is a person of Russian heritage. The post displays a photo of a balloon that says, “Happy 17th Birthday” in Russian, while another X account uses a Russian flag in the bio.
An archived version of another X account shows Nitro telling another user that he planned to “get into contact with my FSB friends,” suggesting that he knows people who work for Russian intelligence.
Henderson’s dismissive post came in response to a post by another X user tagging the FBI and calling on the agency to detain Henderson and “Nitro” based on their apparent foreknowledge of Rupnow’s attack.
Three days later, Henderson posted a link in his diary to a video recording of Nitro giving an interview to an unidentified reporter about the Rupnow shooting. Nitro livestreamed the interview in a Discord group chat as four other anonymous users listened in and typed comments in the chat to help him script his responses.
There was no mistaking in the exchange that took place before the call started that Nitro’s intention was to misdirect the reporter.
“This is going to be fun,” Nitro told the other users in the group chat. “The greatest psy-op ever.”
In a comment in his diary accompanying the link, Henderson remarked that Nitro was “trolling” the reporter, adding a homophobic slur and the text acronym for “laugh out loud.”
During the interview, Nitro admitted that he and Rupnow had interacted in a Discord group chat, while presenting himself as an amused bystander. Based on the coaching from the other members of the chat and their celebratory post-interview assessment, it’s clear what they intended to present as a red herring to explain the motivation behind the attack.
About 10 minutes into the interview, a user with the screen name “Chud King” encouraged Nitro to talk about a concept called “radfem Hitler,” and that was the theme Nitro emphasized during the interview.
“So, radfem Hitler — it’s this really insane bats--- crazy misandrist, like racist woman on Twitter,” Nitro told the reporter. He added that when Rupnow started following the account that supposedly promoted radical feminism and Hitler worship, “that’s kind of when she spiraled.”
Another user in the group chat goes by the name Kristiyan on Discord and X.
In recent X posts, Kristiyan identifies himself as a pan-Slavist. He laments that Eastern Europeans “have this idiotic aggressive pettiness towards the people who are the most similar to them, which is how they end up conquered and taken over by total aliens."
Two days after Donald Trump’s inauguration, Kristiyan expressed disdain for Russian far-rightists who welcome the new U.S. president, writing, “The US will remain an enemy, and I’m grateful things are that way.”
Following Nitro’s phone call with the reporter seeking information about the Rupnow shooting, Kristiyan commented with wry satisfaction: “Journalist owned.”
In addition to playing up the “radfem Hitler” concept as a driver of the attack, Nitro also attempted to minimize connections between Rupnow and another attacker — an 18-year-old named Arda Küçükyetim, who stabbed five people at an outdoor café in the northwestern Turkish city of Eskisehir in August.
“Nobody actually knows about this Arda guy outside of probably people in Turkey, right?” Nitro said. “Nobody’s ever heard of him. He’s such a nothing-burger.”
The reporter asked Nitro whether Rupnow had ever mentioned Küçükyetim.
“No,” Nitro responded.
What Nitro didn’t mention was that both he and Rupnow were in a Telegram chat that had been set up in advance so they could watch Küçükyetim livestream his attack.
Hill at the Center on Extremism told Raw Story that her team found a Telegram chat group where Küçükyetim posted his manifesto. An associate known as “Hansen” then posted a link to a livestream of a promised attack. While the members of the chat group were waiting for the attack to begin, Hill said, Rupnow joined the chat through an invitation link, indicating she had a preexisting relationship with at least one other participant.
Afterwards, members of the chat group critiqued the attack.
By the standards of the accelerationist movement, where success is measured in kill counts, it was a disappointment to them: No one died.
“A for effort,” Nitro wrote in the chat.
“At least he did it,” Hansen said.
Rupnow concurred.
“Credit given for that at least,” she wrote.
This story is the second in a three-part series exploring how violent online subcultures provide the opportunity for teenagers attracted to accelerationism and inceldom to network and encourage one another to carry out terrorist attacks. Read Part 1 here.
