Overview

• FBI received a tip on May 19 about imminent attack plans targeting the Three Rivers Mall in Kelso and identified the suspect by the following day.
• The suspect amassed a small map of the mall and annotated schematics and intended to detonate an improvised chlorine bomb to trigger panic before opening fire.
• Online messages indicate the teenager embraced nihilistic violent extremist ideology and had been plotting the attack since early 2025.
• The Columbia County Sheriff’s Office executed the warrant on May 22 to arrest the youth and the Columbia County District Attorney’s office is prosecuting the case.
• The FBI urged the public to report suspicious behavior and encouraged parents to engage in open dialogue about their children’s online activity.