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Police officers sometimes need to control violent, combative people. Their actions under such circumstances are governed by use-of-force protocols.
Less-lethal technologies give police an alternative to using other physical force options that potentially are more dangerous to officers and suspects. The technologies currently in use include conducted-energy devices (such as Tasers), beanbag rounds, pepper spray and stun grenades.
NIJ Focuses on Making Arrests Safer
The goal of NIJ's less-lethal program is to provide law enforcement and corrections officers with equipment that protects them and the public, reducing the possibility of injury or death. NIJ collaborates with international experts from various fields (for example, medical, scientific, military) when conducting or coordinating research.
Prominent areas of inquiry include:
- Enabling law enforcement and corrections agencies to safely deny individuals or groups access to areas.
- Making projectiles safe at any distance by modeling the technology and techniques that officers can use to deliver less-lethal force.
- Understanding the human health effects of less-lethal technologies, including chemical, kinetic energy and Conducted Energy Devices such as Tasers.
- Analyzing information about incidents of the use-of-force against humans, including the nature of the force applied and the nature of injuries suffered.
Deciding When and How to Use Less-Lethal Devices
When deciding to use less-lethal equipment, officers consider the circumstances and their agency's policy. Almost all larger law enforcement agencies have written policies about the use of less-lethal force.
As part of their policy, agencies often have an approved use-of-force continuum to help officers decide the suitable amount of force for a situation — higher levels of force in most severe circumstances, and less force in other circumstances.
Many agencies in which officers use less-lethal technologies have training programs to help evaluate dangerous circumstances.
Types of Less-Lethal Devices
There are seven types of less-lethal device technologies:
- Conducted Energy Devices. Some CEDs, such as the Taser, can induce involuntary muscle contractions that temporarily incapacitate people. Others deter an individual from a course of action. These include stun guns and stun belts. Learn about research on the safety of CEDs and how they work.
- Directed energy devices. This technology uses radiated energy to achieve the same effect as blunt force, but has a lower probability of injury.
- Chemicals. These chemicals include pepper spray (also known as OC — oleoresin capsicum), tear gas and stink bombs.
Read an NIJ report on the safety and effectiveness of pepper spray.
Read the NIJ Journal article Calming Down: Could Sedative Drugs Be a Less-Lethal Option?
Read a summary of a panel discussion of calmatives as riot control agents (pdf, 10 pages).
- Distraction. This equipment temporarily incapacitates people while causing little harm. Examples include the laser dazzler, bright lights and noise.
- Vehicle-stopping technology. This equipment can stop cars during high-speed chases. Learn more from NIJ's Pursuit Management Web page.
- Barriers. These include nets, foams and physical barriers.
- Blunt force. Projectiles used in crowd-control deter people from a course of action.
Some manufacturers integrate multiple effects into one device. For example, a multisensory stun grenade combines noise, light, chemicals and blunt force. Stun grenades disorient people, giving police officers the opportunity to arrest a suspect without harming them unnecessarily.