Police were called to Jason Lee Elementary School in Northeast Portland Thursday afternoon when a gun in a woman's purse fired.
It happened while she was in the school's cafeteria. No one was hurt.
The woman left the school before police arrived, but they found 27-year-old Antoinette Riley nearby and took her into custody.
She was not carrying the gun. Police searched the area, but weren't able to find the gun. They're warning people in the neighborhood to watch for it and to contact the Portland Police Bureau at 503-823-3333 if it's found.
Riley was lodged at the Multnomah County Jail and has since been released. Riley was charged with Possession of a Firearm in a Public Building.