It could be the most popular back-to-school accessory in the United States: the bulletproof backpack. Since shootings in early August in El Paso, Texas, and Dayton, Ohio, the manufacturers of backpacks say they have recorded a jump in sales.

Available in supermarkets nationwide, the "bulletproof backpack" can stop handgun bullets, such as a 9 mm or .44 Magnum. It could save lives in case of attack, ensure the companies that manufacture it. Some criticize, however, the latter to take advantage of recent mass killings to sell their product to more than 100 dollars. This represents a significant cost for many families.

Last year, 110 fatal shootings occurred in a US school, a record. Some 60 people lost their lives.