While no garment is truly bulletproof, body armor that slows bullets and spreads out their impact have become standard protective gear for military and police personnel. Vests made of bullet-resistant armor cover the wearer’s vital organs, leaving the arms free of the bulky material. Protective armor dates back thousands of years, but the modern bulletproof vest was first invented by Casimir Zeglen around the turn of the 20th century and refined by Richard Davis some 70 years later.

The Protective Priest

Zeglen, a Catholic priest, was dismayed by the assassination of Chicago’s mayor in1893, reports NPR’s Scott Simon; this crime inspired Zeglen to refine the ideas about bulletproof armor he’d been experimenting with since his youth. A contemporary news article described the bulletproof vest as four layers of tightly woven silk, about one-eighth of an inch thick. To resist shots from military-grade weapons, the silk had to be layered over a thin sheet of steel.

The Brave Pizza Guy

Davis, a pizza delivery driver and former marine, was attacked in 1969; the would-be robbery turned into a shootout. Considering how often police officers faced dangerous situations like this, Davis began working on a body armor design that could be concealed underneath everyday clothing. He started out using commercial nylon and the dense fibers of car seat belts, but his second patent, in 1974, used Kevlar, a relatively new synthetic that proved much more resistant than nylon.