NORTON, Mass. (WPRI) — Police have arrested a 13-year-old Norton Middle School student after ammunition was found inside of a locker Wednesday afternoon.

Norton Police Chief Brian Clark said school staff found three rounds of ammunition inside a locker Wednesday after a teacher reported hearing students discussing how the suspect brought bullets to trade for electronic items.

The school canceled its winter concert — which was planned for later that evening — following the discovery as a precaution.

After questioning the students involved, Clark said detectives obtained photos of a rifle sent to one of the students by the suspect.

Police searched the suspect’s home late Wednesday evening and found the rifle and ammunition in the student’s bedroom. Clark said the rifle was consistent with the ammunition found at the school.

The student later arrested and charged with unlawful possession of a firearm.

Superintendent Joseph Baeta said the school district has been working in tandem with police throughout the investigation.

“Student safety is our highest priority,” Baeta said in a statement Wednesday evening.