NEW YORK (AP) — Companies like Guard Dog Security, TuffyPacks and Bullet Blocker are peddling bullet-resistant backpacks for children in time for the back-to-school shopping season. But critics argue they are using tragedy as a marketing opportunity and exploiting parents’ worst fears.

Skyline USA’s founder says he started offering bullet-resistant backpacks for children last year and sold out of them several times after the 2018 Parkland, Florida, school shooting. The founder of TuffyPacks says his backpacks could be the difference between suffering “lethal versus non lethal” injuries.

But some say the companies are driven by profit while others question whether the backpacks will protect their children.

Safety is high on the minds of many parents, especially after two back-to-back mass shootings in El Paso and Dayton, Ohio that left 31 people dead.