During the 1960s, this country witnessed a dramatic rise in law enforcement officer fatalities. From 1966 to 1971, the number of officers killed each year in the line of duty more than doubled, from 57 to 129. Concerned by this rapid increase in officer fatalities and recognizing that a majority of the homicides were inflicted with handguns, the Department of Justice tasked its newly established National Institute of Law Enforcement and Criminal Justice (NILECJ, the predecessor to NIJ) to initiate a research program to investigate the development of lightweight body armor that police officers could wear on duty.
The investigation readily identified several new materials that could be woven into a lightweight fabric with excellent ballistic-resistant properties. Following initial laboratory research, the agency concluded that the objective of producing body armor suitable for full-time police use was achievable. In a parallel effort, the National Bureau of Standards (now known as the National Institute of Standards and Technology) Law Enforcement Standards Office (OLES) developed a performance standard that defined ballistic-resistant requirements for police body armor.
Of all the equipment developed and evaluated in the 1970s by NIJ, one of the most significant was soft body armor. To date, soft body armor has been credited with saving the lives of more than 3,000 law enforcement officers nationally. The NIJ standard for body armor has gained worldwide acceptance as the benchmark for independent performance evaluation of body armor used by criminal justice agencies.
Ballistic-resistant body armor
Ballistic-resistant body armor has been widely available for use by criminal justice personnel for more than 45 years. The dramatic reduction in officer homicides following the introduction of body armor in the mid-1970’s attests to the protection it provides. This success story extends far beyond protection from handguns—more than 3,000 lives have been spared, including cases in which body armor prevented serious injuries to officers from other types of assaults or accidents.
The National Institute of Justice (NIJ) has developed standards for body armor performance since the early 1970’s. The standard for ballistic resistance of body armor was first published in 1972 and has been revised six times, with NIJ Standard 0101.07, Ballistic Resistant Body Armor and the new NIJ Standard 0123.00, Specification for NIJ Ballistic Protection Levels and Associated Test Threats recently published. Click here to learn more about these new standards and how they will be implemented in 2024.
Ballistic-resistant body armor is tested as a part of the NIJ Compliance Testing Program (NIJ CTP) to determine compliance with the NIJ standards. Applicants (body armor manufacturers) who register with the NIJ CTP submit an application package for each model they wish to have tested. Once the NIJ CTP reviews and accepts the application package, a manufacturer submits samples for testing to one of the NIJ-approved independent test laboratories. After completion of the testing process, the NIJ CTP conducts their own review of laboratory’s test report and tested samples to verify the test was performed correctly and maintains tested samples in a secure facility for future comparison and analysis in response to requests for assistance from criminal justice agencies. After successfully meeting all CTP requirements, the CTP will present information on the model and a recommendation to NIJ to approve (or not approve) the model. If NIJ approves the model, the applicant will receive an NIJ Notice of Compliance for the model and it is added to the Compliant Products List (CPL). Once an applicant receives the Notice of Compliance and the model is added to CPL, they can begin to produce the model, and place the NIJ Mark on the label of units sold to criminal justice agencies.
Body Armor Overview page on NIJ.gov
Stab-resistant body armor
Although the most common type of threat faced by a police officer is a ballistic threat, the most common threat faced by correctional officers comes from sharp-edged and pointed weapons. In response to the needs of the corrections community, NIJ developed a test standard for stab- and puncture-resistant body armor. NIJ, through its then-Law Enforcement Standards Office (OLES), partnered with the U.S. Secret Service and the Centre for Applied Science and Technology (CAST, formerly the Home Office and Police Scientific Development Branch) in the United Kingdom (U.K.) to conduct the foundational research that led to the development of NIJ Standard-0115.00, Stab Resistance of Personal Body Armor, published in 2000.
The Home Office has extensive experience in researching the issue of sharp instrument threats, as this is the primary threat faced by law enforcement officers in the UK. The Home Office’s research effort focused on developing a model to be used in determining the actual forces generated during an attack by an assailant with a sharp-edged or pointed instrument. This information could then be used to develop realistic test methodologies and procedures. The Home Office’s researchers reviewed medical data from more than 1,000 actual stabbing assaults that occurred in the UK. Then, to correlate this information, they developed an instrumented knife (dubbed the "stabometer") capable of measuring the amounts of acceleration and force generated by a stabbing impact. The stabometer was then used to record force and energy data generated by 500 fit young military cadets performing a number of different stabbing motions, both overhand and underhand. From this data, researchers developed a greater understanding of the mechanics of a stabbing incident. This in turn led to the development of a dual-mass drop system used in testing, which more accurately replicates the forces impacting a vest during a stabbing incident.
Additionally, several different types of test blades have been developed to accurately reflect actual threats faced by law enforcement and corrections officers. Although these blades are specially designed for testing purposes to ensure consistency in testing, they reflect many of the features found in commercial knives with new blades currently being developed to represent inmate/prisoner made instruments, which are commonly used in attacks against police and corrections officers.
Furthermore, researchers examined the backing material used to support the vest during testing to determine what would most accurately replicate the response of the human torso during a stabbing incident. Once again using data developed by the Home Office, a composite backing material consisting of alternating layers of closed-cell foam and neoprene rubber was developed for use in the testing.
The next revision to this standard, NIJ Standard-0115.01, is in development and anticipated to be published sometime in 2024. Learn more about the effort to develop this new standard here.
Similar to Ballistic-resistant body armor, Stab-resistant body armor is also tested as a part of the NIJ Compliance Testing Program (NIJ CTP) to determine compliance with the NIJ Standard, and the CTP publishes a Compliant Products List (CPL) of models tested and found to comply with the requirements of the NIJ Standard.
Combination armor (ballistic- and stab-resistant)
In some circumstances, a criminal justice agency may have an operational need for body armor that provides both ballistic and stab-resistant protection. A common misconception with body armor is that if it can stop a bullet, it can also stop a knife. This is inaccurate because the methods and materials used for defeating a pointed or sharp-edged weapon are different than what is used for stopping a high-speed bullet. As a result, a manufacturer must research and develop a vest specifically to stop both threats. Additionally, since there is not a single NIJ standard for combination-threat vests, a manufacturer must test the vest independently to both the current NIJ Standards for ballistic-resistance and stab-resistance.
The NIJ CTP provides a Combination Armor CPL to assist criminal justice agencies identify models that have been tested to both the ballistic- and stab-resistant standards and found to comply with both standards.