[60] Shortly after the TurtleSkin work, in 1995 DuPont patented a medium density fabric that was designated as Kevlar Correctional. With an innovative approach to engineering, and a commitment to Research and Development, the company has earned a reputation for reliability, quality and performance. Citation:Terry D. Edwards, (1995) "Felonious killings of state police and highway patrol officers: a descriptive and comparative evaluation", American Journal of Police, Vol. Soon all textile "ice pick" vests began to be adopted by California and other US states as a result of this migration in the test methods. For the higher levels of protection L2 and L3, the very aggressive penetration of the small, thin P1 blade has resulted in the continued use of metallic components in stab armor. [78] Other research has been done to harness nanotechnology to help create super-strong fibers that could be used in future bulletproof vests. Stephan, Restle (1997). A ballistic vest or bullet-resistant vest, often called a bulletproof vest, is an item of body armor that helps absorb the impact and reduce or stop penetration to the torso from firearm-fired projectiles and shrapnel from explosions.. These coatings have been described as shear thickening fluids. Vests that combined stab and ballistic protection were a significant innovation in the 1990s period of vest development. European developments in spherical and hexagonal arrays have resulted in products that have some flex and multi hit performance. One novel approach is use of hook and loop fasteners to assemble the ceramic arrays.[85]. Tex Tech has been working on these materials. Law enforcement carriers in some countries are concealable. Upon impact, the projectiles deformed into a cone shape around the graphene before ultimately breaking through. [71][72] In addition, there are variants of LIBA with multi-hit capacity against threats analogous to 7.62×51mm NATO M993 AP/WC,[73] a tungsten-cored armor-piercing round. Field tests of LIBA have yielded successful results, with 15 AKM hits producing only minor bruises.[74]. The Teijin emphasis appears to be on computational chemistry to define a solution to high tenacity without environmental weakness. A composite-foam and hard-rubber test backing was developed as an alternative to address these issues. [77] In May 2008, the Teijin Aramid group announced a "super-fibers" development program. These new standards created a focus on Level 1 at 25 joules (18 ft⋅lbf), Level 2 at 35 J (26 ft⋅lbf), Level 3 at 45 J (33 ft⋅lbf) protection as tested with the new engineered knives defined in these test documents. The carrier is the visible part of a ballistic vest. The use of body armour while committing a crime is not an additional offense in itself, but may be interpreted as so under different laws such as resisting arrest. Beginning in the early 1990s, an optional test method was approved by California which permitted the use of 10% ballistic gelatin as a replacement for Roma clay. [87] The material was also reportedly able to withstand shock pressures generated by other impacts of up to 250 metric tons-force per square centimeter (24.5 gigapascals; 3,550,000 psi). But steel plates can be 2-3 times as heavy (4 vs. 9 pounds). [citation needed] There are many shops in Europe that sell ballistic vests and body armor, used or new. If the impact stress can be spread out over a large enough area that the cone moves out at an appreciable velocity compared with the velocity of the projectile, stress will not be localized under where it hit. The introduction of knives which cut fiber and a hard-dense test backing required stab vest manufacturers to use metallic components in their vest designs to address this more rigorous standard. The military type of carrier, English police waistcoat carrier, or police tactical carrier most typically has a series of webbing, hook and loop, and snap type connectors on the front and back face. The vest absorbs the energy from the deforming bullet, bringing it to a stop before it can completely penetrate the textile matrix. The clean and jerk is a close-grip, two-move lift. This standard, like the stab standards, is based on drop testing with a test knife in a mounting of controlled mass. Parallel to the US development of "ice pick" vests, the British police, PSDB, was working on standards for knife-resistant body armor. In order to test at a representative velocity, an air cannon method was developed to propel the knife and sabot at the vest target using compressed air. The use of commercial knives with inconsistent sharpness and tip shape created problems with test consistency. As vest manufacturers and the specifying authorities worked with these standards, the UK and US Standards teams began a collaboration on test methods. The cost of ballistic fibers increases dramatically as the yarn size decreases, so it's unclear how long this trend can continue. The most basic carrier includes pockets which hold the ballistic panels and straps for mounting the carrier on the user. In Italy, the purchase, ownership and wear of ballistic vests and body armor is not subject to any restriction, except for those ballistic protections that are developed under strict military specifications and/or for main military usage, thus considered by the law as "armament materials" and forbidden to civilians.