A science teacher in Newtown, Connecticut was charged Wednesday after bringing a concealed gun to the school, the Hartford Courant reported.

Security personnel detained Jason M. Adams after he was spotted with the firearm Wednesday morning at Newtown Middle School, according to the newspaper. Police then charged Adams with possessing a weapon on school grounds, after which he was released without bond.

The school district put Adams, who has a valid pistol permit, on leave while it conducts an investigation, according to the report.

December marked the third anniversary of the Sandy Hook Elementary School massacre in Newtown, which left 26 people, including 20 children, dead.

Adams is expected in court April 20, according to the Courant.