MOUNT HOLLY, N.C. — Bulletproof backpack inserts claim to offer an extra level of protection for your children as threat of school shootings continues to be unpredictable in the U.S. But do they work?

The company's products - like virtually every bulletproof backpack on the market - are advertised as meeting "Ballistic Level IIIA" standards, which means they can withstand bullets from handguns and ...