Since 1972, the National Institute of Justice (NIJ) has been setting minimum performance standards to ensure that the unique equipment used by law enforcement and other criminal justice agencies meet their requirements. NIJ has published roughly 60 standards, many of which were the first of their kind both in the United States and internationally. The first NIJ performance standard was for police body armor. That standard has been revised seven times since it was first published, each iteration responding to evolving changes in threats, body armor design, and practitioner requirements.