(Portland, OR) -- A teenager is in police custody after the Portland FBI thwarted a planned mass shooting at a Washington state mall. The FBI learned of a threat against the Three Rivers Mall in Kelso. The suspect was identified as a juvenile from Columbia County, Oregon. He was arrested May 22nd. The FBI says he had the means, map and a specific plan. He was allegedly going to use a chlorine bomb to cause panic, and then shoot people in the mall as they fled. He also planned to kill himself. The suspect is being prosecuted in Columbia County Juvenile Court.