FBI release - PORTLAND, Ore.- The FBI Portland Field Office and local law enforcement partners arrested a Columbia County, Ore., juvenile who conspired to conduct an improvised explosive attack and mass shooting at the Three Rivers Mall in Kelso, Wash., on May 22, 2025.  The teen, whose name will not be released due to an effort to limit public disclosure of a minor, was arrested on the morning of May 22, 2025, by deputies from the Columbia County Sheriff’s Office.  The detailed and imminent attack plans were reported to the FBI on May 19, 2025. Immediately, the FBI began working with our partners to identify the suspect who was  responsible for the threat. The subject was identified the next day, May 20, as a juvenile Columbia County resident who shared nihilistic violent extremist ideology and the plans in online chats. The suspect was placed under court-authorized surveillance for public safety concerns, and a federal search warrant was planned and executed on May 22, 2025, prior to the arrest.  The suspect demonstrated the intent and means to carry out their plan, which included precise details such as a map of the mall, a route the shooter would follow, a plan to use an improvised explosive device commonly known as a chlorine bomb to incite panic, and then to shoot mall patrons as they were exiting the movie theatre before ultimately committing suicide at a pre-determined location in the mall.  An alarming amount of indicators of a cogent path to violence were met - at no point in this plan did it seem like the suspect wouldn’t follow through with their plans.  “This plot was as serious as it gets,” said FBI Portland Special Agent in Charge Douglas A. Olson. “We, along with our partners, moved swiftly to interrupt this violent plan and to protect our community.”  Initial contact with the subject was made by the FBI, however the arrest was made by local law enforcement on state charges.  The FBI encourages the public to report suspicious behavior to law enforcement, and for parents to engage with their children and have an open dialogue about their online activity.  The Columbia County District Attorney’s office is prosecuting this case.