EVERGREEN, Colo. – Last week’s shooting at Evergreen High School has prompted pointed questions about federal and nonprofit monitoring of extremism, and specifically what authorities knew about the shooter before the tragedy unfolded.
Central to the inquiry is the timeline of FBI and Anti-Defamation League (ADL) monitoring of social media activity that has now been linked to the 16-year-old student who perpetrated the attack.
FBI Investigation Preceded Evergreen Shooting by Months
Disturbing online activity first came onto federal radar in July 2025, when the ADL notified the FBI about several concerning posts by an unidentified user that referenced previous mass shootings, exhibited white supremacist imagery, and included anti-Semitic rhetoric, reports 9News.
Related Article: Reading Between the Lines: Recognizing Insider References to School Shooters
The FBI launched an investigation but was unable to identify the person responsible for the posts. The posts are now believed to be from the gunman of last week’s Evergreen High School shooting, which injured two students. The gunman died by suicide after being confronted by law enforcement officers at the school.
Shooter’s Social Media Activity Revealed Obsession with Other Attacks
According to the ADL, the shooter’s social media profiles contained multiple references to White supremacist symbolism, including a photograph of himself wearing a skull mask linked to the Christchurch mosque shootings in New Zealand where 51 people were killed and 89 were injured.
Additionally, he had emulated the perpetrators of the Columbine High School massacre in his online posts, reports Denver7.
Campus Safety previously reported that since December, the gunman had been very active on a website popular with previous school shooters that hosts extremely graphic and gory materials.
The two other school shooters the ADL identified as frequenting the site before they carried out their attacks include the Abundant Life Christian School gunman and Antioch High School gunman.
