WPXI-TV reports that the weapon wasn't found until after school, when another student told a bus driver that someone had a gun.

Children are not required to go through the metal detectors at Pittsburgh Faison Elementary School in Homewood, but a district spokesperson told WPXI that there are going to be changes in security measures starting Tuesday morning.

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The kindergarten student had the loaded gun, with the safety on, in his backpack, inside his locker.

Officials told WPXI that parents got a notice from the district's phone system.

WPXI is working to find out if the child's parents will be charged.