In the United States, police officers don’t wear a stab-proof vest. Instead, they usually wear ballistic body armor, since they are much more likely to be shot than to be stabbed. However, in the United Kingdom, and some European Union countries, on-duty police officers wear stab vests, since knife attacks are much more common.
Even in the United States, correctional officers, who work inside prisons are more likely to wear a stab-proof vest rather than ballistic protection vests. Since there aren’t any guns inside prisons that inmates can access, stabbing attacks with an edged blade or an improvised spike are much more common. Most stab vests are designed to stop stabbing attacks and blunt trauma attacks with blunt objects. Therefore, they can protect correctional officers from serious injuries.
In some situations, customs officers, transit officers, and immigration officers may also use stab vests, since they work in controlled environments where guns are not easy to get, however, improvised stabbing weapons are a more likely threat.