The FBI was tipped off months ago about concerning social media posts made by the teenage gunman accused of shooting two of his classmates last week at a Colorado high school, according to a report.
The agency had been investigating 16-year-old Desmond Holly’s alarming, far-right online activity since July, but did not know his identity at the time, Fox News Digital reported.
Holly, who died by suicide after opening fire at Evergreen High School last Wednesday, had been active on an online forum where users watch videos of killings and violence, and spent a significant amount of time online engaging with content featuring extremist ideologies and violence.
“We continued to work this assessment investigation to identify the name and location of the user up and until September 10, 2025,” the FBI told Fox in a statement.
“During the assessment investigation, the identity of the account user remained unknown, and thus there was no probable cause for arrest or additional law enforcement action at the federal level,” the agency added.
The Anti-Defamation League also looked into Holly’s online activity, which it says revealed a fascination with mass shootings and white supremacy.
"Holly had an account on the gore forum WatchPeopleDie, where he had commented on posts about shootings in Parkland (2018), Buffalo (2022) and at a Quebec City mosque (2017)," the ADL said in a report published Friday.
Holly is one of several recent mass attackers who have been active on the so-called “gore forum,” according to the ADL.
The report claims the teen collected tactical gear that he covered “with extremist symbols” and posted “content emulating former shooters such as Rupnow and the 1999 Columbine High School shooters.”
The Columbine shooting, which left 14 people dead, took place in Jefferson County, which is also where Evergreen High School is located.
The ADL’s investigation also revealed how Holly’s TikTok accounts contained white supremacist symbols, and the name of his most recent account included a reference to a popular white supremacist slogan.
Several days before Wednesday’s shooting, Holly posted a video on TikTok posing in a similar way to how the Wisconsin shooter posed before killing two people in December. He also included a photo of the Wisconsin shooter in a post in which Holly wore a black T-shirt with “WRATH” written on it.
Holly also posted videos showing how he had made a shirt similar to the one worn by a gunman in the Columbine shooting, the ADL said.
Some TikTok posts shared by the ADL showed a user encouraging Holly to be a “hero,” a term the ADL says white supremacists use to refer to successful ideologically motivated attackers.
That user also told Holly to get a patch with a Nazi-era symbol that was worn by the men who carried out the 2019 attack on a mosque in Christchurch, New Zealand, and the 2022 attack on a supermarket in Buffalo, New York.
TikTok confirmed the accounts associated with Holly had been banned.
