Armadillo Skin': the Bulletproof backpack insert Cotroneo lives in the same county as Great Mills High School, where in 2018 a shooter opened fire in the hallway, killing a 16-year-old girl.

So reads an advertisement for BulletBlocker, a company selling bulletproof backpacks and other body armor for children. Since the tragic school shooting in Newtown, Conn., that left 20 children ...