A 15-year-old sophomore at Glen Burnie High School was arrested Tuesday after a loaded .22-caliber handgun was found in his backpack, authorities said.

The student was charged as a juvenile with a weapons violation and taken to the Cheltenham Youth Facility in Prince George's County, according to Anne Arundel County police.

School officials discovered the Marino Ware revolver -- loaded with seven rounds -- after the student was seen returning to campus during the day, police said. Where the student obtained the gun and his reasons for having it are under investigation, they said.