Bob Vernon, formerly with the Los Angeles Police Department, tells of how the Department would test bullet-proof vests—and demonstrate to rookie officers their value—by placing them on mannequins and then shooting round after round at them. They’d then check to see if any of the rounds penetrated the vests. Invariably the vests would pass the test with flying colors. Vernon would then turn to the rookie officers and ask, “So who wants to wear it now instead of the mannequin?”

Source unknown