MEDFORD, Mass. (AP) — A Massachusetts superintendent has announced he will retire early after it was revealed he knew about a gun ammunition magazine found at a middle school weeks before it was reported to police.

Medford Superintendent Roy Belson announced his retirement during a school committee meeting Tuesday. Belson will retire April 30, close to a month earlier than expected.

Many parents called for him to step down after it was revealed that he knew about a loaded gun magazine found at McGlynn Middle School in December.

Officials say Principal Jake Edwards threw the magazine away while cleaning his office Dec. 20. Edwards has since been placed on administrative leave.

Medford schools closed Monday for a staff review of security policies and a sweep of the building. Classes resumed Tuesday.