The massacres in Texas and Ohio, which left 31 dead in a single day, have seen a surge in sales on children’s Kevlar backpacks as well as guns.
Sales of the reinforced bags have soared by up to 300 percent as parents in the States rush to protect their children following the attacks.
And FBI records, based on criminal record checks on people buying weapons, show sales are up at gun shops too.
Lori Alhadeff, whose daughter Alyssa was one of 17 students shot dead at a school in Florida last year, says her sons will have bulletproof backpacks.
She said: “For my boys to go back to school, I required that they have bulletproof backpacks to protect their vital organs. I have to do everything I can to protect them.”
Naomi Winch, a school board candidate in eastern Pennsylvania, said: “I considered bulletproof backpacks this year for my three boys.”
However it is unclear whether the bags, which sell for up to $200 (£166), are effective.
Tests have shown that they do not stop bullets from high-powered weapons such as the semi-automatic rifles used in the recent mass shootings.
Gun control activists warned the sales will only instil fear in children and pushed for background checks and bans on semi-automatic rifles.
However US president Donald Trump has refused to ban the weapons and has been reluctant to support universal background checks.
The checks are not supported by the National Rifle Association (NRA), the powerful gun lobby that donates almost exclusively to Republicans.
Mr Trump said he was speaking to the NRA to find common ground on background checks.
“I think we can have some really meaningful background checks,” he said. “We don’t want people that are mentally ill, people that are sick, we don’t want them having guns.”