Module 2 - Law Enforcement Equipment and Police Canines

Kevlar is five times stronger than steel, yet it is extremely lightweight. Kevlar does not rust or corrode and it readily absorbs vibrations. Kevlar is expensive because special precautions are necessary to handle the concentrated sulfuric acid used in its manufacture.

Kevlar breaks down when exposed to the ultraviolet rays in sunlight; hence, it is not used unprotected or unsheathed. Dry-cleaning agents, bleach, and repeated washing can also negatively affect Kevlar. To protect against all these problems, the layers of Kevlar in bullet-resistant vests have fabric coverings to prevent exposure to sunlight and moisture.

Kevlar is made in three common grades: Kevlar, Kevlar 29, and Kevlar 49. Kevlar is typically used as in tires. Kevlar 29 is used in body armour, industrial cables, asbestos replacements, and brake linings. Kevlar 49 is used in applications such as plastic reinforcement for boat hulls, airplanes, and bicycles.

Bullet-Resistant Vests Used in Policing

Most North American police officers engaged in frontline law enforcement now wear bullet-resistant vests. However, as the name implies, bullet-resistant vests do not prevent injury from edged weapons that police officers may encounter, such as knives, arrows, or ice picks. Because the force of a blow from such weapons is focused on a very small area, knives and other pointed objects can penetrate many layers of Kevlar causing injury or death. However, specially designed vests that protect against edged weapons are often worn by correctional officers.

Bullet-resistant vests provide protection from most low and medium-velocity handgun bullets but not high-velocity rifle rounds. Hard body armour consisting of a ceramic or metal plate inserted into a pocket in the front of a bullet-resistant vest greatly increases the protection offered by a bullet-resistant vest. These trauma plates are smaller than the front panel of a vest, and they are surrounded by several layers of Kevlar that prevent bullet fragments from ricocheting from the trauma plate after impact. An additional protection helps prevent injury to the heart, lungs, and ribs that may arise from “blunt force trauma”, a type of injury sustained by the sudden force of a bullet hitting but not quite penetrating a vest. Blunt force trauma can cause severe bruising, cracked ribs, or even death.

Higher threat protection levels can be achieved with additional layers of Kevlar and heavier trauma plates, but these forms of hard body armour are rigid, heavy, and bulky. They are impractical for routine use by uniformed patrol officers. Tactical team members typically wear such types of body armour for short periods when dealing with high-risk incidents involving the use of firearms.