A gun was left in the bathroom of a Michigan public school by an armed guard paid to protect it, according to the school’s director. The Chatfield School, a charter school that teaches K-8 students, hired a retired police weapons instructor to provide armed protection after the massacre at Sandy Hook Elementary. The result wasn’t exactly what they intended:

The security officer “made a breach in security protocol” and left an unloaded weapon in a restroom “for a few moments,” said Chatfield School Director Matt Young.

Young said the school has been in contact with local authorities about the matter and wouldn’t discuss any possible repercussion for the officer, calling it “a personnel matter.” Young also declined to name the security officer.

Experts on gun violence believe that armed guards are unlikely to deter or head off school shootings. Guards also have a track record of abusing students, often in a racially discriminatory fashion.