According to the United Nations’ Code of Conduct for Law Enforcement Officials “Law enforcement officials may use force only when strictly necessary and to the extent required for the performance of their duty” (United Nations, 1979). However, they often have to determine in a matter of seconds whether force is necessary in a particular situation and, if so, exactly how much is proportional to the threat they face. Police officers on patrol were traditionally armed only with a service revolver and a baton. However, since the mid-20th century, law enforcement agencies have provided their officials with a range of personal protective equipment and less-lethal weapons to be used in circumstances of civil disturbance to disperse riots or to incapacitate individual rioters, or in hostage rescue or other police operations.

Less-lethal weapons (LLWs) are weapons that have a lower risk of causing death or serious injury. The UK’s College of Policing defines LLWs as: “weapon systems designed to be used by law enforcement directly against an individual or group of individuals to achieve a physical effect in order to mitigate a threat, without substantial risk to the subject of permanent or serious injury, or death” (College of Policing, 2020). The United Nation’s definition of less-than lethal weapons are even more comprehensive: “Weapons that are explicitly designed and primarily employed so as to incapacitate personnel or materiel while minimizing fatalities, permanent injury to personnel and undesired damage to property and the environment” (United Nations, 2015). LLWs are important to reduce reliance on methods that are capable of causing death or serious injury. The United Nations has therefore called on all governments and law enforcement agencies to develop and equip law enforcement officials with non-lethal incapacitating weapons that would allow for a differentiated use of force in appropriate situations (United Nations, 1990). In crowd management situations they must also comply with regional and international human rights standards (African Commission on Human and Peoples’ Rights, 2017). A 2010 study in the USA found that between 15 and 20 percent of arrests involve use of force. Their analysis of more than 24,000 use-of-force cases showed that the injuries of suspects substantially decreased when LLWs were used (Bulman, 2011)(Smith, 2010). Another review of data collected over a nine year period (2005–2013) in the United States of 33 police force events that involved kinetic impact projectiles, only one event resulted in a moderate injury requiring hospital admission (Beatty, 2020). LLWs are also used extensively by the South African Police Service, Public Order Police, prison warders and others.

There are five basic types of disabling mechanism used by LLWs currently in use by law enforcement agencies worldwide; impact, irritant chemicals, electric shock, intense sound and intense light. The United Nations currently recognizes the following eight types of LLWs (United Nations, 2015 & 2020):

1. Police batons

Police batons are made out of wood, rubber, plastic, or metal, and come in a variety of lengths. The most common types are straight batons, side-handle batons (also known as tonfa batons), and telescopic batons.

2. Kinetic impact projectiles

Kinetic impact projectiles are designed to inflict pain and incapacitate an individual without penetrating the body. Kinetic impact projectiles are deployed from a wide range of launchers and shotguns. The most common types are rubber bullets, plastic bullets, impact rounds, baton rounds and bean bags.

3. Water cannons

Water cannons are vehicles designed to project water for the purpose of dispersal of groups, or to put an end to violent behaviour.

4. Hand-held chemical irritants

Hand-held chemical irritants are usually contained within a pressurized spray container as a fine powder, although they may also come in liquid form, and consists of one or more of the following irritants: OC (oleoresin capsicum; chemical formula: C18H27NO3) or PAVA (pelargonyl vanillylamide; chemical formula: C17H27NO3), both known as “pepper spray”, and CN (Phenacyl chloride, also known as chloroacetophenone; chemical formula: C6H5COCH2Cl) and CS (2- chlorobenzalmalononitrile, also called o-chlorobenzylidene malononitrile; chemical formula: C10H5ClN2), both known as “tear gas”. CN is the principal component of the aerosol agent Mace that affects mainly the eyes. CS is a stronger irritant that causes burning sensations in the respiratory tract and involuntary closing of the eyes, but its effects wear off more quickly, after only 5 to 10 minutes of breathing fresh air.

5. Chemical irritants launched at a distance

Gas/ smoke canisters are thrown by hand or launched by large bore (typically 37 to 40 mm) guns. Gas canisters contain chemical irritants, such as tear gas (CS or CN) or pepper spray (OC or PAVA), whereas smoke canisters produce a thick cloud that can be used as a defensive screen by police forces.

6. Conducted electrical weapons

These are weapons that deliver an electric shock aimed at temporarily disrupting muscle functions and/ or inflicting pain. Conducted electrical weapons include electrified batons and shields, and projectiles that administer the shock through thin flexible wires, e.g. tasers1. 1 Taser is an abbreviation of Thomas Appleton Swift’s Electrical Rifle, and was inspired by the young adult novel Tom Swift and His Electric Rifle by Victor Appleton, published in 1911.

7. Acoustic weapons

Acoustic weapons such as infrasound, ultrasound and directional speakers can be used to immobilize, disable, control or disperse crowds of people. Stun canisters, also known as flash/bang rounds, are also acoustic weapons.

8. Dazzling weapons

Dazzling weapons use visible light that is bright enough to cause temporary blindness. They use, for example, lasers or light-emitting diodes (LEDs) to achieve this effect.

LLWs are designed to minimise the risk of death or serious injuries when used as intended. However, any of these weapons can inflict severe injuries or result in a fatality if used improperly, which is why weapons and ammunition of this type are known as “less-lethal” rather than “non-lethal”. Although the prevalence of cases where the use of LLWs has led to serious injuries or deaths is relatively small, such cases invariably receive negative publicity and accusations of “police brutality”. People have been killed by rubber bullets, especially if shot at close range. Another major risk from the use of rubber bullets is eye injuries, including permanent blinding (Ifantides, 2020). During recent protests in Austin, USA, police used beanbag munitions for crowd control, resulting in numerous clinically significant injuries (Olson, 2020). Tear gas can also kill, particularly if used in confined spaces. Young children and people with asthma are among those most at risk. Conducted electrical weapons can have adverse cardiac effects. The Washington based Police Executive Research Forum found that conducted electrical weapons fail in as many as one-third or more of their deployments (PERF, 2020). Dazzling weapons may cause permanent blindness and acoustic weapons could cause deafness. An investigation by the Institute for Security Studies (Bruce, 2019) found that the main LLWs used by the South African Police Service in crowd management are batons, rubber bullets, teargas, stun grenades, water cannons and long-range acoustic devices, whereas tonfa batons and electrified shields are used in South African prisons. The investigation found evidence of LLWs being abused by Public Order Police units and in South African prisons. They found that the regulatory framework of the Public Order Police gives extremely limited recognition to the risks associated with LLWs, whereas the Department of Correctional Services has a more extensive regulatory framework.

Everyone has the right to assemble freely with others. The right to assembly may be exercised in a number of ways, including through meetings, funerals, processions, rallies, sit-ins, protests and demonstrations (African Commission on Human and Peoples’ Rights, 2017). The injudicious use of LLWs on protesters can be seen as repressing the democratic right to protest and can cause police to lose legitimacy among the public and the protesters (McCartney, 2015). Use of force by the police to achieve a lawful objective, such as making a lawful arrest, acting in self defence or protecting others, must in all circumstances be reasonable and proportionate (College of Policing, 2020). This also applies to crowd control. LLWs should only be used when other less harmful means will be ineffective, and must exercise particular caution when using LLWs that are indiscriminate in their effects or endangering uninvolved persons (African Commission on Human and Peoples’ Rights, 2017). Many LLWs, such as tear gas, are indiscriminate weapons as they currently cannot be targeted at an individual. Acoustic weapons such as stun grenades and long-range acoustic devices are also indiscriminate (Bruce, 2019). This requires that the development and deployment of LLWs should be carefully evaluated and controlled (United Nations, 1990). Police forces should record and analyse the operational use of force, including the use of LLWs, to build an evidence base to learning which can be reflected in the development of policy, training and tactics to improve safety for all (College of Policing, 2020). Training should include the proper use of LLWs and should include both theoretical and scenario based training, as well as shooting at static or interactive targets (African Commission on Human and Peoples’ Rights, 2017). When all these factors are in alignment - policy, training, tactics, technology, and culture - the policing profession is likely to see positive movement in use-of-force statistics and improvements in police community relations (PERF, 2020). Technological innovation will no doubt provide better and safer LLWs in the future. New LLWs such as the Byrna HD Personal Security Device is already gaining popularity amongst private citizens, security guards and police officers as a non-lethal alternative to firearms for self defence (Byrna, 2020). Law enforcement officers need to consider their own safety while intervening in violent confrontations, and often need to keep a safe distance between themselves and the suspects. There is therefore also a need for long range LLWs (Haynes, 2018). The current generation of gun-launched kinetic impact and chemical irritant projectiles are potentially lethal when shot as short range and dangerously inaccurate at long range. This is due to the fact that the projectiles have high aerodynamic drag and are unstable in flight. The technology to overcome this problem is already available (Buys, 2017). The Defence and Security Accelerator, part of the UK Ministry of Defence, is currently seeking proposals for innovative technologies that allow law enforcement officers to safely prevent the escalation of conflict in serious or violent circumstances from a distance (DASA, 2020). The desired LLW system should be able to accurately, reliably and temporarily stop a violent or armed individual from causing harm from distances between 0m and 70m and have the ability for the police to initiate and maintain communication and visual contact with the subject. Another development is that of remote controlled LLWs. Although the use of remote-controlled LLWs for the policing of assemblies is discouraged (African Commission on Human and Peoples’ Rights, 2017), their development is highly likely. Remote-controlled LLWs such as unmanned aerial systems (UAS) have big potential to increase the safety in law enforcement, both of officers and the public. Such systems will increasingly be used to accurately fire non-lethal munitions in life threatening situations such as clearing buildings from armed criminals and incapacitating barricaded hostage keepers (Tumbarska, 2018). An unmanned aerial system (UAS) would include an unmanned aerial vehicle (UAV), commonly known as a “drone”, a ground-based controller, and a system of communications between the two. The flight of UAVs may operate with various degrees of autonomy: either under remote control by a human operator or autonomously by onboard computers (ICAO, 2011). The procurement of LLWs by State Parties must be subject to independent review of their compliance with regional and international human rights standards. If such weapons are used, law enforcement officials must be trained in the use of such equipment, remain actively in control of the delivery of force, limit the use to circumstances in which it is justified, reasonable, proportionate and necessary, and use the equipment in a manner that minimises the risk of physical or mental harm to all persons (African Commission on Human and Peoples’ Rights, 2017).