Five Dubuque school buildings were locked down for a time yesterday after a teen was spotted with gun.Dubuque police received a report of an armed teenager behind a restaurant. Police spotted the teen a short time later and he fled into the backyard of a home. Five schools were locked down until the boy was caught. Cops say the gun was an air pistol and they believe it had been stolen from an area store. The boy has been identified as 14-year-old Tonio Koopmann of Dubuque. He is charged with carrying a concealed weapon, possession of alcohol under the legal age, interference with officials acts and theft.