There have been more than 230 school shootings in the United States over the past decade and active shooter drills have become routine in students’ lives. Now, technologies developed to protect soldiers in war are being incorporated into everyday objects of childhood school days. At a recent educational trade show, a booth displaying backpacks with removable ballistic shields — riddled with bullet marks from testing — was set between booths for the textbook company McGraw Hill and the learning toy Speak & Spell. Some of these products come from major brands like 3M; others are designed by entrepreneurial parents. One thing they all have in common: they’re expensive ($185 for a pencil case, $450 for a bulletproof hoodie, $60,000 for a classroom shelter). Despite advertisements that tout official protection ratings by the National Institute of Justice, a federal agency, the institute declared such claims “false” and said that it has never tested nor certified any bullet-resistant items except body armor for law enforcement. “School security measures and so-called ‘target hardening’ are extraordinarily expensive and so far, there is not scientific evidence that they make schools safer,” said Dewey Cornell, an expert in classroom safety at the University of Virginia who has trained threat assessment teams in thousands of schools. Steve Naremore, owner of the ballistic shield company TuffyPacks, acknowledged that it was a “morbid industry.” He said that he sold tens of thousands of products to parents within a week of the school shooting in Uvalde, Texas. “People say, ‘Oh, you’re just profiting off the carnage,’ ” he said. “And you know what I say? ‘Look, don’t blame me. I’m just the fire extinguisher manufacturer, OK?’” One common marketing tactic is to emphasize kid-friendly aesthetics — whimsical colors, patterns and adorable characters.