THORNTON, Colo. (CBS4)– A Thornton high school student who allegedly brought a handgun to school last week has been formally charged.

The 15-year-old was taken into custody on Friday after police said a loaded 9mm handgun was found in his backpack. He has been charged with possession of a weapon on school grounds, possession of a handgun by a juvenile and carrying a concealed weapon.

The teen, who has not been identified because he is a juvenile, appeared in Adams County District Court for advisement of formal charges Thursday. He has been released to his mother on a $5,000 personal recognizance bond.

The gun was found in the student’s backpack on Aug. 21. It was loaded with three rounds in the magazine and did not have a round chambered in a firing position.

Investigators say the student had not made any threats to students of staff. Police have not released where the teen obtained the gun.