Arizona fire captain Kevin Goodman says his company, Escape Armour, exists for one reason: to prevent the loss of even a single child in a school shooting.

Goodman, who has four children, designed a bulletproof vest that easily fits into school backpacks, so kids can have it with them at all times. It's not the first such product, but he says his armour uses better materials.

"So to be able to make something that possibly could protect a child in this kind of horrible situation some time, I mean, that's why I do it," he told Reuters.

Goodman, who has worked as a firefighter, fire captain and fire investigator, as well as an engineer, in Arizona since 1998, took Reuters outside Phoenix city limits to demonstrate how the vest works.

Using a mannequin to simulate a child, he fired several shots using a 9mm rifle, 9mm handgun and .45-caliber handgun.

As he removed an armour plate from the vest - which did not let any bullets through - he commented on where each shot hit.

"These two hits here would have pierced right through my heart. These on the on the right side would have gone through my right lung. And these lower ones over here, there's two hits here, these would have easily gone through my left side lung," Goodman said.

Escape Armour offers two different products: a foldable vest that comes in three sizes and a standalone shield that makes any backpack bulletproof.

Nineteen children and two teachers were killed in Uvalde, Texas, on May 24, in the deadliest U.S. school shooting in a decade. It ended when officers who had waited nearly an hour to storm the classroom shot the gunman dead.

There have been at least 239 mass shootings in the United States this year, according to the Gun Violence Archive, a non-profit research group.

(Editing by Gerry Doyle; Editing by Robert Birsel)