The 16-year-old boy who shot two of his fellow students at Evergreen High School in Colorado on Sept. 10 appeared to hint at his plans on social media just hours before the shooting took place, according to research from the Anti-Defamation League
The anti-hate and anti-extremism organization's Center for Extremism said the teen was also active on a violent gore forum website that has been tied to at least two other school shooting suspects.
Authorities in Colorado said last week that investigators believed the teen had been "radicalized by some extremist network," but did not offer specific details.
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During the school's lunch hour, the teen fired a revolver handgun that he had loaded multiple times around the school campus before he turned the gun on himself. Two students were injured and transported to a local hospital.
According to the Scripps News Group in Denver, the FBI investigated the teen's social media accounts months ago after receiving a tip from the ADL about the concerning content but could not identify the individual behind the accounts at the time.
The ADL said the teen "spent substantial amounts of time in online spaces featuring extremist ideologies and violent content, ultimately adopting extremist views himself," but the group did not say exactly what extremist views were identified.
The teen joined a violent gore forum in December 2024. He had reportedly commented on posts in the forum related to the mass shootings in Parkland (2018), Buffalo (2022) and at a Quebec City mosque (2017), the ADL said.
The organization said two other individuals accused of conducting school shootings in Madison, Wisconsin, and in Nashville, Tennessee, were also known to have used the online forum.
The ADL said the teen posted content on the forum that showed he collected tactical gear, adorned that gear with extremist symbols and emulated former shooters such as the 1999 Columbine High School shooters. Evergreen High School is located approximately 20 miles west of where the infamous Columbine High School shooting took place and is part of the same county.
"Like many attackers, [he] assembled his gear in a piecemeal fashion, drawing inspiration from the equipment used by previous mass shooters," the ADL said. "For example, [he] posted a now-deleted TikTok video in which he modelled a tactical helmet and a gas mask; the post’s background music featured a Serbian folk song that [name removed] played while livestreaming the 2019 Christchurch Mosque shootings."
There were several exchanges in the teen's social media posts that the ADL said suggested he may have intended or hoped to livestream the attack on Sept. 10.
The ADL said the teen's social media accounts were "filled with white supremacist symbolism," including certain terms in his username, wearing white supremacist patches and promoting Nazi-era symbols.
Just two hours before the shooting took place, the ADL said the teen reposted a photo of a revolver and box of ammunition on his X account. He had previously shared the same image on Sept. 5.
