Establishment of Interdisciplinary Working Group for Review of Kinetic Energy Munitions Final Report 2010 [open pdf - 1MB]
"Of approximately 1,200 officers killed in the line of duty since 1980, it is estimated that more than 30% could have been saved by body armor. According to the James Guelff Body Armor Act, the risk of dying from gunfire is fourteen times higher for an officer not wearing a vest. In addition, the US Department of Justice estimates that 25% of state, local, and tribal law enforcement officers are not issued body armor. Since establishing the IACP/DuPont™ Kevlar® Survivors' Club® in 1987; over 3,000 law enforcement personnel have survived both ballistic and non-ballistic incidents because they were wearing body armor. Body armor is comprised of fibers that have been woven together into sheets. Numerous sheets are used to make up one ballistic panel. The sheets work individually and together to help prevent the penetration of the bullet. Some materials that are used include: Kevlar®, Spectra® Fiber, Aramid Fiber, and Dyneema. The material fibers work to absorb and spread the energy over the entire torso so all of the energy from the impact is not focused on one area of the body, resulting in serious injury. Standards are set by the National Institute of Justice (NIJ) for the amount of deformation that is allowed into a person's torso, this is termed backface signature. With body armor becoming more pliable, more deformation is experienced and a certain type of injury has become more prevalent and is known as the backface signature injury. This is defined as an open wound that almost resembles a bullet wound, however, in these cases the bullet is captured in the armor and doesn't perforate the vest. With these injuries becoming more common, the current standard for body armor should be evaluated to ensure officers are not at an increased risk."
National Criminal Justice Reference Center: https://www.ncjrs.gov/