Law enforcement stopped a planned mass shooting last month at Three Rivers Crossing in Kelso, the Portland Office of the FBI reported Thursday during a press conference.
A juvenile conspired the mass shooting, as well an explosive attack, at the mall located at 351 Three Rivers Dr.
The FBI said there was no specific date for the attack, but that the suspect had everything in place to carry out the plan at any time.
The Portland office reports the juvenile is from Columbia County, Oregon, but the teen’s name will not be released.
Authorities did not describe the sex or age of the teen.
Cities in Columbia County include Rainier, Clatskanie, St. Helens, Scappoose, Columbia City, Prescott and Vernonia.
Columbia County Sheriff’s Office deputies arrested the teen the morning of May 22.
Detailed plans of the attack were reported to the FBI on May 19.
Law enforcement discovered the teen’s identity the day after. The teen shared violent, extreme ideology in online chats, which authorities followed through court-authorized surveillance, the FBI reports.
A federal search warrant was issued the morning of the teen’s arrest.
The FBI states the teen’s plans were posted online and included a map of the mall, the shooter’s route, and a way to use what officials call “an improvised explosive device commonly known as a chlorine bomb.”
The plan was to create panic, then shoot patrons as they exited the movie theater, then commit suicide in the mall, the FBI reports.
The movie theater inside the mall is a Regal theater.
FBI Portland Special Agent in Charge Douglas Olson said in a press release that “this plot was as serious as it gets.”
The Columbia County District Attorney’s office will be prosecuting the case.
The FBI reported charging documents for the teen would be released later Thursday.
A tracker by the Associated Press and USA Today reports there have been six massing killings in the U.S. in 2025 so far.
The report defines mass killings as random and unpredictable, in which four or more people have died, not including the perpetrator, within a 24-hour period.
A press conference detailing the information was held earlier on Thursday, which included media outlets such as The Oregonian, but The Daily News was not contacted, and TDN staff followed up with the FBI afterward.
The Kelso mall was purchased in November by Bob Davis and Eric Pucci, who rebranded it from Three Rivers Mall to Three Rivers Crossing.
An unrelated fire was also reported Sunday evening at T Nails & Beauty Supplies, located in the mall near the Kelso Public Library. The nail salon is currently closed due to damages.
