
Riot control is a form of
public order policing
Protest policing or public order policing is part of a state’s response to political dissent and social movements. Police maintenance of public order during protest is an essential component of liberal democracy, with military response to prote ...
used by
law enforcement
Law enforcement is the activity of some members of the government or other social institutions who act in an organized manner to enforce the law by investigating, deterring, rehabilitating, or punishing people who violate the rules and norms gove ...
,
military
A military, also known collectively as armed forces, is a heavily armed, highly organized force primarily intended for warfare. Militaries are typically authorized and maintained by a sovereign state, with their members identifiable by a d ...
,
paramilitary
A paramilitary is a military that is not a part of a country's official or legitimate armed forces. The Oxford English Dictionary traces the use of the term "paramilitary" as far back as 1934.
Overview
Though a paramilitary is, by definiti ...
or
security forces
Security forces are statutory organizations with internal security mandates. In the legal context of several countries, the term has variously denoted police and military units working in concert, or the role of irregular military and paramilitar ...
to
control, disperse, and
arrest
An arrest is the act of apprehending and taking a person into custody (legal protection or control), usually because the person has been suspected of or observed committing a crime. After being taken into custody, the person can be question ...
people who are involved in a
riot
A riot or mob violence is a form of civil disorder commonly characterized by a group lashing out in a violent public disturbance against authority, property, or people.
Riots typically involve destruction of property, public or private. The p ...
, unlawful
demonstration or unlawful
protest
A protest (also called a demonstration, remonstration, or remonstrance) is a public act of objection, disapproval or dissent against political advantage. Protests can be thought of as acts of cooperation in which numerous people cooperate ...
.
If a riot is spontaneous, then actions which cause people to stop and think (e.g. loud noises or issuing instructions in a calm tone) can be enough to stop it. However, these methods usually fail when there is severe anger, or the riot was planned or organized. Riot control personnel have long used
less lethal weapons such as
batons and whips to disperse crowds and detain rioters. Since the 1980s, riot control officers have also used
tear gas
Tear gas, also known as a lachrymatory agent or lachrymator (), sometimes colloquially known as "mace" after the Mace (spray), early commercial self-defense spray, is a chemical weapon that stimulates the nerves of the lacrimal gland in the ey ...
,
pepper spray
Pepper spray, oleoresin capsicum spray, OC spray, capsaicin spray, mace, or capsicum spray is a Tear gas, lachrymator (tear gas) product containing as its active ingredient the chemical compound capsaicin, which irritates the eyes with burning ...
,
rubber bullet
Rubber bullets (also called rubber baton rounds) are a type of baton round. Despite the name, rubber bullets typically have either a metal core with a rubber coating, or are a homogeneous admixture with rubber being a minority component. Altho ...
s,
stun grenades
A stun grenade, also known as a flash grenade, flashbang, thunderflash, or sound bomb, is a non-lethal explosive device used to temporarily disorient an enemy's senses. Upon detonation, a stun grenade produces a blinding flash of light and an ...
, and electric
taser
Taser (stylized in all caps) is a line of handheld conducted energy devices (CED) sold by Axon Enterprise (formerly Taser International). The device fires two small barbed darts intended to puncture the skin and remain attached to the targe ...
s. In some cases, riot squads may also use
Long Range Acoustic Devices,
water cannon
A water cannon is a device that shoots a high-velocity stream of water. Typically, a water cannon can deliver a large volume of water, often over dozens of meters. They are used in firefighting, large vehicle washing, riot control, and mining. ...
s,
armoured fighting vehicle
An armoured fighting vehicle (British English) or armored fighting vehicle (American English) (AFV) is an armed combat vehicle protected by vehicle armour, armour, generally combining operational mobility with Offensive (military), offensive a ...
s,
aerial surveillance
Surveillance aircraft are aircraft used for surveillance. They are primarily operated by military forces and government agencies in roles including intelligence gathering, maritime patrol, battlefield and airspace surveillance, observation (e.g ...
,
police dog
A police dog, also known as a K-9 (phonemic abbreviation of canine), is a dog that is trained to assist police and other law enforcement officers. Their duties may include searching for drugs and explosives, locating missing people, findin ...
s or
mounted police
Mounted police are police who patrol on horseback or camelback. Their day-to-day function is typically picturesque or ceremonial, but they are also employed in crowd control because of their mobile mass and height advantage and increasingly in th ...
on horses. Persons performing riot control typically wear protective equipment such as
riot helmets, face visors,
body armor
Body armour, personal armour (also spelled ''armor''), armoured suit (''armored'') or coat of armour, among others, is armour for human body, a person's body: protective clothing or close-fitting hands-free shields designed to absorb or deflect ...
(vests, neck protectors, knee pads, etc.),
gas mask
A gas mask is a piece of personal protective equipment used to protect the wearer from inhaling airborne pollutants and toxic gases. The mask forms a sealed cover over the nose and mouth, but may also cover the eyes and other vulnerable soft ...
s and
riot shield
A riot shield is a lightweight protection device, typically deployed by riot police and some military unit during protest, though also utilized by protestors. Riot shields are typically long enough to cover an average-sized person from the top of ...
s. Even though riot tactics are effective in controlling crowds, they can also lead to significant psychological effects on both the rioters and the police. Exposure to intense fear, stress, and violence during these confrontations can result in long-term mental health issues, like anxiety, post-traumatic stress disorder (PTSD), and heightened aggression, which can impact the well-being of protesters and police officers.
There have been cases where lethal weapons are used to violently suppress a protest or riot, as in the
Tbilisi Massacre,
Nika Riots in the Roman Empire,
Boston Massacre
The Boston Massacre, known in Great Britain as the Incident on King Street, was a confrontation, on March 5, 1770, during the American Revolution in Boston in what was then the colonial-era Province of Massachusetts Bay.
In the confrontati ...
,
Haymarket Massacre,
Banana Massacre,
Hungarian Revolution of 1956
The Hungarian Revolution of 1956 (23 October – 4 November 1956; ), also known as the Hungarian Uprising, was an attempted countrywide revolution against the government of the Hungarian People's Republic (1949–1989) and the policies caused by ...
,
Kent State Shootings
The Kent State shootings (also known as the Kent State massacre or May 4 massacre"These would be the first of many probes into what soon became known as the Kent State Massacre. Like the Boston Massacre almost exactly two hundred years before (Ma ...
,
Soweto Uprising
The Soweto uprising, also known as the Soweto riots, was a series of demonstrations and protests led by black school children in South Africa during apartheid that began on the morning of 16 June 1976.
Students from various schools began to p ...
,
Sharpeville massacre,
Mendiola Massacre
The Mendiola massacre was an incident that took place on Mendiola Street, San Miguel, Manila, Philippines on January 22, 1987, in which state security forces under President Corazon Aquino violently dispersed a farmers' march to Malacañang ...
,
Bloody Sunday (1905)
Bloody Sunday (, ), also known as Red Sunday (), was the series of events on Sunday, in St Petersburg, Russia, when demonstrators, led by Father Georgy Gapon, were fired upon by soldiers of the Imperial Guard as they marched towards the Wi ...
,
Ponce massacre
The Ponce massacre was an event that took place on Palm Sunday, March 21, 1937, in Ponce, Puerto Rico, when a peaceful civilian Marching, march turned into a police shooting in which 17 civilians and two policemen were killed, and more than 200 ...
,
Río Piedras massacre,
Bloody Sunday (1972)
Bloody Sunday, or the Bogside Massacre, was a massacre on 30 January 1972 when British soldiers shot 26 unarmed civilians during a protest march in the Bogside area of Derry, Northern Ireland. Thirteen men were killed outright and the death o ...
,
1989 Tiananmen Square protests
The Tiananmen Square protests, known within China as the June Fourth Incident, were student-led Demonstration (people), demonstrations held in Tiananmen Square in Beijing, China, lasting from 15 April to 4 June 1989. After weeks of unsucces ...
,
2017 Venezuelan protests,
2018–2019 Gaza border protests,
2022 Sri Lankan protests
The 2022 Sri Lankan protests, commonly known as Aragalaya (), were a series of mass protests that began in March 2022 against the government of Sri Lanka. The government was heavily criticized for mismanaging the Economy of Sri Lanka, Sri Lankan ...
,
2022 Kazakh unrest
The 2022 Kazakh unrest, also known as January Events, Bloody January, or the January Tragedy, was a series of Political demonstration, mass protests and Civil disorder, civil unrest that began in Kazakhstan on 2 January 2022 after a sudden ...
and
Mahsa Amini protests
Civil unrest and protests against the Government of Iran, government of the Islamic Republic of Iran associated with the Death in custody, death in police custody of Death of Mahsa Amini#Victim, Mahsa Amini () began on 16 September 2022 and ca ...
.
History
Maintaining order during demonstrations and quenching riots has always been a challenge for governments and administrations. Until early in the 20th century, no dedicated force really existed in most countries and the traditional response when the regular police force proved inadequate was to call upon the army, often with disastrous results: either
fraternization
Fraternization (from Latin ''frater'' meaning "brother") is the act of establishing intimate relations between people or groups. It is generally used to refer to establishing relations that are considered unethical, controversial, problematic, or i ...
or use of excessive violence.
The terminology arguably first arises in the
Keystone Cops
The Keystone Cops (often spelled "Keystone Kops") are fictional, humorously incompetent policemen featured in silent film slapstick comedies produced by Mack Sennett for his Keystone Film Company between 1912 and 1917.
History
Hank Mann creat ...
short "
A Hash House Fraud" in 1915.
In France, for example, several revolts were fueled by poor handling by the military. The
National Gendarmerie
The National Gendarmerie ( ) is one of two national law enforcement forces of France, along with the National Police (France), National Police. The Gendarmerie is a branch of the French Armed Forces placed under the jurisdiction of the Minister ...
created specialized "mobile" gendarmerie forces several times during the 19th century in times of trouble but these units were disbanded soon after the end of the troubles they had been tasked to handle and there was no permanent organization in place until it was finally decided in 1921 to create "Mobile Gendarmerie platoons" within the
Departmental Gendarmerie
The Departmental Gendarmerie () is the territorial police branch of the French National Gendarmerie. The Departmental Gendarmerie has regular contact with the population and conducts local policing functions throughout the French territory.
T ...
. These platoons, either horse mounted or on foot were composed of 40 gendarmes each (60 in the Paris Region). In 1926, the platoons formed the "Garde Républicaine mobile" (mobile republican guard or GRM), which became a distinct branch of the Gendarmerie in 1927, the platoons becoming part of companies and legions. By 1940, the GRM was a force 21,000 strong, composed of 14 Légions, 54 company groups and 167 companies.
Long the only large force specialized in maintaining or restoring law and order in France during demonstrations or riots, the GRM progressively developed the doctrine and skills needed in that role: exercise restraint, avoid confrontation as long as possible, always leave an "exit door" for the crowd, etc. In 1940, after the fall of France, the German authorities had the GRM disbanded but it was reinstated in 1944 and renamed
Mobile Gendarmerie
The Mobile Gendarmerie () (GM) is a subdivision of the French National Gendarmerie whose main mission is to maintain public order (from crowd control to riot control) and general security. Contrary to the Departmental Gendarmerie, whose jurisdic ...
in 1954.

The first squad trained in modern techniques of riot control in Asia was formed in 1925 in
colonial Shanghai
Shanghai, Shanghainese: , Standard Chinese pronunciation: is a direct-administered municipality and the most populous urban area in China. The city is located on the Chinese shoreline on the southern estuary of the Yangtze River, with the ...
as a response to the mismanaged riot of the
May Thirtieth Movement
The May Thirtieth Movement () was a major labor and anti-imperialist movement during the middle-period of the Republic of China era. It began when the Shanghai Municipal Police opened fire on Chinese protesters in Shanghai's International Set ...
.
New policing methods, including
combat pistol shooting Combat pistol shooting is a modern martial art that focuses on the use of the handgun as a defensive weapon for self defense, or for military and police use. Like most martial arts, combat pistol shooting is practiced both for defense and for sport ...
,
hand to hand combat
Hand-to-hand combat is a physical confrontation between two or more persons at short range (grappling distance or within the physical reach of a handheld weapon) that does not involve the use of ranged weapons.Hunsicker, A., ''Advanced Skills in ...
skills, and
knife fight
A knife fight is a violent physical confrontation between two or more combatants in which one or more participants are armed with a knife.MacYoung, Marc, ''Winning A Street Knife Fight'', (Digital format, 70 min.), Boulder, CO: Paladin Press, ( ...
training, were pioneered by British Assistant Commissioner
William E. Fairbairn
Lieutenant colonel (United Kingdom), Lieutenant Colonel William Ewart Fairbairn (; 28 February 1885 – 20 June 1960) was a British soldier and police officer. He developed hand-to-hand combat methods for the Shanghai Police during the interwar ...
and officer
Eric Anthony Sykes of the
Shanghai Municipal Police
The Shanghai Municipal Police (SMP; ) was the police force of the Shanghai Municipal Council which governed the Shanghai International Settlement between 1854 and 1943, when the settlement was retroceded to Chinese control.
Initially composed of ...
as a response to a staggering rise in armed crime in the
Shanghai
Shanghai, Shanghainese: , Standard Chinese pronunciation: is a direct-administered municipality and the most populous urban area in China. The city is located on the Chinese shoreline on the southern estuary of the Yangtze River, with the ...
had become one of the world's most dangerous cities due to a breakdown in law and order in the country and the growth of
organised crime
Organized crime is a category of transnational, national, or local group of centralized enterprises run to engage in illegal activity, most commonly for profit. While organized crime is generally thought of as a form of illegal business, some ...
and the
opium trade
Opium (also known as poppy tears, or Lachryma papaveris) is the dried latex obtained from the seed capsules of the opium poppy ''Papaver somniferum''. Approximately 12 percent of opium is made up of the analgesic alkaloid morphine, which is ...
.
Under Fairbairn, the SMP developed a myriad of riot control measures. These riot control techniques led to the introduction of Shanghai's "Reserve Unit", used to forcibly disband riots and respond to high-level crimes such as
kidnapping
Kidnapping or abduction is the unlawful abduction and confinement of a person against their will, and is a crime in many jurisdictions. Kidnapping may be accomplished by use of force or fear, or a victim may be enticed into confinement by frau ...
s and
armed robberies. The skills developed in Shanghai have been adopted and adapted by both international police forces and clandestine warfare units. Fairbairn was again the central figure, not only leading the Reserve Unit, but teaching his methods around the world, including in the
United States
The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...
, and colonial
Cyprus
Cyprus (), officially the Republic of Cyprus, is an island country in the eastern Mediterranean Sea. Situated in West Asia, its cultural identity and geopolitical orientation are overwhelmingly Southeast European. Cyprus is the List of isl ...
and the
Straits Settlements
The Straits Settlements () were a group of British territories located in Southeast Asia. Originally established in 1826 as part of the territories controlled by the British East India Company, the Straits Settlements came under control of the ...
.
Modern Examples
Black Lives Matter protests
George Floyd
George Perry Floyd Jr. (October 14, 1973 – May 25, 2020) was an African-American man who was murdered by a white police officer in Minneapolis, Minnesota, during an arrest made after a store clerk suspected Floyd had used a counterfeit tw ...
was a Black man who was murdered by a Minneapolis Police Officer in May of 2020 during an arrest. Subsequently, many Americans protested for ''
Black Lives Matter
Black Lives Matter (BLM) is a Decentralization, decentralized political and social movement that aims to highlight racism, discrimination and Racial inequality in the United States, racial inequality experienced by black people, and to pro ...
.'' The summer of 2020 oversaw a large number of mass protests for Black Lives Matter to address systemic bias in police departments. Due to the high volume of protests, police departments and sparsely the National Guard were sent to end the long protests. Police departments often wore riot gear and used both projectiles and irritants to disperse the protesters. These incidents were widely documented through the use of social media. Documentation and support for the protests further facilitated the movement. One study, recorded by the National Institute of Health, studied the usage of social media as well as its contributions to the movement's legitimacy. Counter-protesters as well as right wing militia committed violence against the protesters in addition to police departments. Instead of irritants or other standardized tools for riot control, these counter-protesters often used more violent techniques such as ramming into protesters with their cars. Data supports that Black Lives Matter protests in particular were faced with much more state intervention. Suppression techniques that were used by both the state and right wing counter-protesters resulted in injury and death. Both during and after the protests, there were many pieces of legislation that either were passed or were written to curb these protests. Law makers and the public questioned riot control and its violations of the First Amendment including the right to assembly and the right to free speech. 45 U.S. states had considered this legislation. Concerns were raised by both political parties on the distinction between riots and protests.
Peru protests
Between 2022 and 2023, several
protests in Peru erupted who were against the Congress and President Dina Bolurate. In December of 2022, the government suspended several constitutional rights. These included the right to prevent troops from entering and staying in one's home, the freedom of movement, and the freedom of assembly. The force used against the protesters resulted in at least six hundred injuries and sixty deaths. Spain had traditionally funded the government in past years and continued to do so to provide weaponry and funding to dismantle these protests. The NGO Amnesty International called on Spain to discontinue these exports citing it as "lethal repression." The security forces came in with assault weapons and in one incident opened fire on protesters. Amnesty International interpreted that the President should be held criminally responsible for the deaths and injuries that the protesters had sustained.
Equipment
For protection, officers that are trained in police anti-riot schools performing riot control will often wear protective helmets and carry riot shields. These are designed to protect the wearer from those dangers that come from direct
melee
A melee ( or ) is a confused hand-to-hand combat, hand-to-hand fight among several people. The English term ''melee'' originated circa 1648 from the French word ' (), derived from the Old French ''mesler'', from which '':wikt:medley, medley'' and ...
and hurled objects such as bottles and bricks. The gear frequently worn by riot control officers protects the entire body with no vulnerable spots to exploit. For example, the helmets worn by riot control officers have an additional outward-extending part that protects the back of the neck from assault. To provide even greater protection, the protective equipment often provides ballistic protection. If tear gas or other riot control agents are to be used,
gas mask
A gas mask is a piece of personal protective equipment used to protect the wearer from inhaling airborne pollutants and toxic gases. The mask forms a sealed cover over the nose and mouth, but may also cover the eyes and other vulnerable soft ...
s may also be worn. While the visual of police in full riot gear may be intimidating, today's riot suits are designed to minimize injuries and prevent fatalities for both officers and citizens. This evolution of riot gear signifies a move towards
less-than-lethal
Non-lethal weapons, also called nonlethal weapons, less-lethal weapons, less-than-lethal weapons, non-deadly weapons, compliance weapons, or pain-inducing weapons are weapons intended to be lethality, less likely to kill a living target than c ...
tactics and de-escalation approaches. Contemporary riot gear incorporated innovations such as
tear gas
Tear gas, also known as a lachrymatory agent or lachrymator (), sometimes colloquially known as "mace" after the Mace (spray), early commercial self-defense spray, is a chemical weapon that stimulates the nerves of the lacrimal gland in the ey ...
,
rubber bullets, batons,
pepper spray
Pepper spray, oleoresin capsicum spray, OC spray, capsaicin spray, mace, or capsicum spray is a Tear gas, lachrymator (tear gas) product containing as its active ingredient the chemical compound capsaicin, which irritates the eyes with burning ...
, and
tasers
Taser (stylized in all caps) is a line of handheld conducted energy devices (CED) sold by Axon Enterprise (formerly Taser International). The device fires two small barbed darts intended to puncture the skin and remain attached to the targe ...
, which contributes to minimizing injuries and casualties for all parties involved. These advancements have revolutionized crowd control by shifting from relying on
lethal force
Deadly force, also known as lethal force, is the use of force that is likely to cause serious bodily injury or death to another person. In most jurisdictions, the use of deadly force is justified only under conditions of extreme necessity a ...
to employing more
less-than-lethal
Non-lethal weapons, also called nonlethal weapons, less-lethal weapons, less-than-lethal weapons, non-deadly weapons, compliance weapons, or pain-inducing weapons are weapons intended to be lethality, less likely to kill a living target than c ...
methods that prioritize public safety and safeguard the well-being of law enforcement officers.
One of many additional concerns is to prevent people in the crowd from snatching officers'
side arms, which may be stolen or even used against the police. In a very heavy crowd, the officer may not be able to see who is responsible for snatching a weapon, and may not even notice that it has happened. For this reason,
riot police
Riot police are police who are organized, deployed, trained or equipped to confront crowds, protests or riots.
Riot police may be regular police officers who act in the role of riot police in particular situations, or they may be separate unit ...
may have
holster
A handgun holster is a device used to hold or restrict the undesired movement of a handgun, most commonly in a location where it can be easily withdrawn for immediate use. Holsters are often attached to a belt or waistband, but they may be atta ...
s with positive locking mechanisms or other extra means of retention, if their agencies can afford such tools. However, this can be a trade-off that increases the amount of time needed to draw the sidearm in an emergency. Alternately, riot police may not carry sidearms at all.
The initial choice of
tactics
Tactic(s) or Tactical may refer to:
* Tactic (method), a conceptual action implemented as one or more specific tasks
** Military tactics, the disposition and maneuver of units on a particular sea or battlefield
** Chess tactics
In chess, a tac ...
determines the type of offensive equipment used. The base choice is between
lethal (e.g. 12 gauge
shotgun
A shotgun (also known as a scattergun, peppergun, or historically as a fowling piece) is a long gun, long-barreled firearm designed to shoot a straight-walled cartridge (firearms), cartridge known as a shotshell, which discharges numerous small ...
) and
less-than-lethal weaponry (e.g.
tear gas
Tear gas, also known as a lachrymatory agent or lachrymator (), sometimes colloquially known as "mace" after the Mace (spray), early commercial self-defense spray, is a chemical weapon that stimulates the nerves of the lacrimal gland in the ey ...
,
pepper spray
Pepper spray, oleoresin capsicum spray, OC spray, capsaicin spray, mace, or capsicum spray is a Tear gas, lachrymator (tear gas) product containing as its active ingredient the chemical compound capsaicin, which irritates the eyes with burning ...
,
plastic bullet
Plastic bullet can refer to:
* Plastic baton round: a large, blunt, low-velocity projectile fired from a specialized gun, intended as a less-lethal weapon for riot control and an alternative to rubber bullets.
* Plastic bullet: a conventionall ...
s,
taser
Taser (stylized in all caps) is a line of handheld conducted energy devices (CED) sold by Axon Enterprise (formerly Taser International). The device fires two small barbed darts intended to puncture the skin and remain attached to the targe ...
s,
batons, and other
incapacitant
Non-lethal weapons, also called nonlethal weapons, less-lethal weapons, less-than-lethal weapons, non-deadly weapons, compliance weapons, or pain-inducing weapons are weapons intended to be less likely to kill a living target than convention ...
s). The decision is based on the perceived level of threat and the existing laws; in many countries it is illegal to use lethal force to control riots in all but the most extreme circumstances.
Special riot hand weapons include the
wooden or rubber baton; the African
sjambok
The sjambok (), or litupa, is a heavy leather Whip (implement), whip. It is traditionally made from adult hippopotamus or rhinoceros hide, but it is also commonly made out of plastic.
A strip of the animal's hide is cut and carved into a strip ...
, a heavy leather or plastic whip, and the Indian
lathi, a long cane with a blunt metal tip. Vehicle-mounted
water cannon
A water cannon is a device that shoots a high-velocity stream of water. Typically, a water cannon can deliver a large volume of water, often over dozens of meters. They are used in firefighting, large vehicle washing, riot control, and mining. ...
s may serve to augment personal weapons. Some water cannons let police add
dye
Juan de Guillebon, better known by his stage name DyE, is a French musician. He is known for the music video of the single "Fantasy
Fantasy is a genre of speculative fiction that involves supernatural or Magic (supernatural), magical ele ...
to mark rioters or tear gas to help disperse the crowds.
In major unrest, police in
armoured vehicles may be sent in following an initial subduing with firepower. Occasionally,
police dog
A police dog, also known as a K-9 (phonemic abbreviation of canine), is a dog that is trained to assist police and other law enforcement officers. Their duties may include searching for drugs and explosives, locating missing people, findin ...
s, fire hoses, or
mounted police
Mounted police are police who patrol on horseback or camelback. Their day-to-day function is typically picturesque or ceremonial, but they are also employed in crowd control because of their mobile mass and height advantage and increasingly in th ...
are deployed.
File:Bastille 2007-05-06 anti Sarkozy 487645689 c9fce856e3 o.jpg, French gendarmes mobiles using tear gas
File:Bastille 2007-05-06 anti Sarkozy 487623928 37656cd319 o.jpg, This gendarme
A gendarmerie () is a paramilitary or military force with law enforcement duties among the civilian population. The term ''gendarme'' () is derived from the medieval French expression ', which translates to "men-at-arms" (). In France and som ...
is shooting tear gas canisters using an Alsetex "Cougar" launcher
File:Vietnamprotestors.jpg, U.S. Army
The United States Army (USA) is the primary land service branch of the United States Department of Defense. It is designated as the Army of the United States in the United States Constitution.Article II, section 2, clause 1 of the United Stat ...
troops attempting to keep Vietnam War protesters
Vietnam, officially the Socialist Republic of Vietnam (SRV), is a country at the eastern edge of mainland Southeast Asia, with an area of about and a population of over 100 million, making it the world's fifteenth-most populous coun ...
from rioting in Washington, D.C.
Washington, D.C., formally the District of Columbia and commonly known as Washington or D.C., is the capital city and federal district of the United States. The city is on the Potomac River, across from Virginia, and shares land borders with ...
, 1967.
File:VOA Arrott - A View of Syria, Under Government Crackdown 07.jpg, Syrian riot control in Damascus
Damascus ( , ; ) is the capital and List of largest cities in the Levant region by population, largest city of Syria. It is the oldest capital in the world and, according to some, the fourth Holiest sites in Islam, holiest city in Islam. Kno ...
in 2012
File:Warszawa, Marsz Niepodległości 2011 05.jpg, Polish riot control police in Warsaw
Warsaw, officially the Capital City of Warsaw, is the capital and List of cities and towns in Poland, largest city of Poland. The metropolis stands on the Vistula, River Vistula in east-central Poland. Its population is officially estimated at ...
at the March of Independence in 2011
File:Riot police by the building of the Cabinet of Ministers.jpg, Defensive line of "Berkut" unitmen in riot gear
Riot control is a form of public order policing used by law enforcement, military, paramilitary or security forces to control, disperse, and arrest people who are involved in a riot, unlawful demonstration or unlawful protest.
If a riot is sp ...
by the Cabinet of Ministers building in Kyiv
Kyiv, also Kiev, is the capital and most populous List of cities in Ukraine, city of Ukraine. Located in the north-central part of the country, it straddles both sides of the Dnieper, Dnieper River. As of 1 January 2022, its population was 2, ...
during 2013 Euromaidan
Euromaidan ( ; , , ), or the Maidan Uprising, was a wave of Political demonstration, demonstrations and civil unrest in Ukraine, which began on 21 November 2013 with large protests in Maidan Nezalezhnosti (Independence Square) in Kyiv. The p ...
protests.
File:Policiais Manifestacoes 20170209.jpg, Riot control group of Rio de Janeiro Police in confrontation with protesters in the historical center of the city.
File:Reparto Celere.jpg, Italian ''Celerini'' in the 1950s.
File:Police Protesters Clash after Eid Prayers in Kashmir 2 Sept 2017 29.jpg, Pellet shotguns have been used by Indian security forces for crowd control in Jammu and Kashmir against stone pelting mobs.
File:Water Cannon used on İstiklâl Caddesi near Taksim Square - Gezi Park, İstanbul - Flickr - Alan Hilditch.jpg, Intervention vehicle for social events that interfered with demonstrators in Gezi Park (Istanbul
Istanbul is the List of largest cities and towns in Turkey, largest city in Turkey, constituting the country's economic, cultural, and historical heart. With Demographics of Istanbul, a population over , it is home to 18% of the Demographics ...
) in 2013
Riot control agent (RCA)
Riot control agents (sometimes called RCAs) are
non-lethal
Non-lethal weapons, also called nonlethal weapons, less-lethal weapons, less-than-lethal weapons, non-deadly weapons, compliance weapons, or pain-inducing weapons are weapons intended to be less likely to kill a living target than convention ...
lachrymatory agents used for riot control. Most commonly used riot control agents are
pepper spray
Pepper spray, oleoresin capsicum spray, OC spray, capsaicin spray, mace, or capsicum spray is a Tear gas, lachrymator (tear gas) product containing as its active ingredient the chemical compound capsaicin, which irritates the eyes with burning ...
and various kinds of tear gas. These chemicals enable to disperse a protesting or
riot
A riot or mob violence is a form of civil disorder commonly characterized by a group lashing out in a violent public disturbance against authority, property, or people.
Riots typically involve destruction of property, public or private. The p ...
ing crowd, or to clear a building. They can rapidly produce sensory irritation or disabling physical effects which usually disappear within 15 minutes (for tear gas) and up to 2 hours (for pepper spray) following termination of exposure. They can also be used for
chemical warfare defense training, but their use in warfare itself is a violation of Article I.5 of the
Chemical Weapons Convention
The Chemical Weapons Convention (CWC), officially the Convention on the Prohibition of the Development, Production, Stockpiling and Use of Chemical Weapons and on their Destruction, is an arms control treaty administered by the Organisation for ...
. Article II.9 of the CWC specifically authorizes their use for domestic law enforcement.
Pepper spray

The active ingredient in pepper-spray is
capsaicin
Capsaicin (8-methyl-''N''-vanillyl-6-nonenamide) (, rarely ) is an active component of chili peppers, which are plants belonging to the genus ''Capsicum''. It is a potent Irritation, irritant for Mammal, mammals, including humans, and produces ...
, which is a chemical derived from the fruit of plants in the ''
Capsicum
''Capsicum'' () is a genus of flowering plants in the Solanum, nightshade family Solanaceae, native to the Americas, cultivated worldwide for their edible fruit, which are generally known as "peppers" or "capsicum". Chili peppers grow on five s ...
'' genus, including
chilies. Desmethyldihydrocapsaicin, a synthetic analogue of capsaicin also known as pelargonic acid vanillylamide or PAVA, is used in another version of pepper spray known as PAVA spray and used in the
United Kingdom
The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Northwestern Europe, off the coast of European mainland, the continental mainland. It comprises England, Scotlan ...
. Another synthetic counterpart of pepper spray,
pelargonic acid morpholide
4-Nonanoylmorpholine ''pelargonic acid morpholide, N-nonanoylmorpholine, MPK or МПК (for ), or MPAis an amide of pelargonic acid and morpholine.
Properties
4-Nonanoylmorpholine was first synthesized in 1954 by L. M. Rice, from morpholine and ...
, was developed and is widely used in
Russia
Russia, or the Russian Federation, is a country spanning Eastern Europe and North Asia. It is the list of countries and dependencies by area, largest country in the world, and extends across Time in Russia, eleven time zones, sharing Borders ...
. Its effectiveness compared to natural pepper spray is uncertain and it reportedly has caused some injuries. When undesirables threaten an area, such as a riot after a soccer game, riot police are called in to subdue them. In these situations, the police may use pepper spray, or water cannons to neutralize the threat.
Pepper spray typically comes in canisters, which are often small enough to be carried or
concealed in a pocket or purse. Pepper spray can also be bought concealed in items such as
rings. There are also
pepper spray projectiles available, which can be fired from a
paintball gun
A paintball marker, also known as a paintball gun, paint gun, or simply marker, is an air gun used in the shooting sport of paintball, and the main piece of paintball equipment. Paintball markers use compressed gas, such as carbon dioxide (CO2) ...
. Having been used for years against demonstrators, it is increasingly being used by police in routine interventions.
Tear gas
Tear gas is a non-specific term for any
chemical
A chemical substance is a unique form of matter with constant chemical composition and characteristic properties. Chemical substances may take the form of a single element or chemical compounds. If two or more chemical substances can be combin ...
that is used to temporarily incapacitate through irritation of eyes and/or respiratory system. It is used as a hand-held spray or can be fired in canisters that heat up spewing out an
aerosol
An aerosol is a suspension (chemistry), suspension of fine solid particles or liquid Drop (liquid), droplets in air or another gas. Aerosols can be generated from natural or Human impact on the environment, human causes. The term ''aerosol'' co ...
cloud at a steady rate.
While the use of tear gas in warfare is prohibited by various international treaties
[e.g. the ]Geneva Protocol
The Protocol for the Prohibition of the Use in War of Asphyxiating, Poisonous or other Gases, and of Bacteriological Methods of Warfare, usually called the Geneva Protocol, is a treaty prohibiting the use of chemical and biological weapons in ...
of 1925: 'Prohibited the use of "asphyxiating gas, or any other kind of gas, liquids, substances or similar materials"' that most countries have signed, use by police and for private self-defense is not banned by these treaties.
Popular tear gases include the eye irritants
ortho-chlorobenzylidene-malononitrile (CS gas),
chloroacetophenone (CN gas), and
dibenz (b,f)-1,4-oxazepine (CR gas). Among a long list of substances, these three have become of greater importance than the others because of their effectiveness and low risks when used. Today, CS has largely replaced CN as the most widely used tear gas internationally.
Decontamination
At room temperature, tear gases are white solids. They are stable when heated and have low
vapor pressure
Vapor pressure or equilibrium vapor pressure is the pressure exerted by a vapor in thermodynamic equilibrium with its condensed phases (solid or liquid) at a given temperature in a closed system. The equilibrium vapor pressure is an indicat ...
. Consequently, they are usually dispersed as
aerosol
An aerosol is a suspension (chemistry), suspension of fine solid particles or liquid Drop (liquid), droplets in air or another gas. Aerosols can be generated from natural or Human impact on the environment, human causes. The term ''aerosol'' co ...
s. All of them have low
solubility
In chemistry, solubility is the ability of a chemical substance, substance, the solute, to form a solution (chemistry), solution with another substance, the solvent. Insolubility is the opposite property, the inability of the solute to form su ...
in water but can be dissolved in several
organic solvent
A solvent (from the Latin '' solvō'', "loosen, untie, solve") is a substance that dissolves a solute, resulting in a solution. A solvent is usually a liquid but can also be a solid, a gas, or a supercritical fluid. Water is a solvent for p ...
s.
Hydrolysis
Hydrolysis (; ) is any chemical reaction in which a molecule of water breaks one or more chemical bonds. The term is used broadly for substitution reaction, substitution, elimination reaction, elimination, and solvation reactions in which water ...
of CN is very slow in a water solution, especially if
alkali
In chemistry, an alkali (; from the Arabic word , ) is a basic salt of an alkali metal or an alkaline earth metal. An alkali can also be defined as a base that dissolves in water. A solution of a soluble base has a pH greater than 7.0. The a ...
is added. CS is rapidly hydrolyzed in water solution (half-life at
pH 7 is about 15 min. at room temperature) and extremely rapid when alkali is added (half-life at
pH 9 is about 1 min.). CR is hydrolyzed only to a negligible extent in water solution.
CN and
CR are, thus, difficult to decompose under practical conditions, whereas
CS can easily be inactivated by means of a water solution. Skin is suitably decontaminated of CS and CN gas by thorough washing with soap and water. CS is then decomposed, whereas CN is only removed via soap and water. The effects of CR gas are greatly increased by water, causing any attempt to DECON CR via soap and water to increase the severity and duration of the effects. When decontamination of CR is attempted with soap and water the effects of CR can last up to 48 hours
Decontamination of material after contamination with CR gas is not possible for up to 45 days. CS can be decontaminated l with a 5–10 percent soda solution or 2 percent alkaline solution. If this type of decontamination cannot be accomplished (e.g., contaminated rooms and furniture), then the only other means is by intensive air exchange—preferably with hot air. Exposed streets and sidewalks will have toxic and irritating CS powder that will be stirred into the air by traffic and pedestrians long after the cloud has dissipated, and should be washed away with water. In contrast to human beings, domesticated animals generally have lower sensitivity to tear gases. Dogs and horses can therefore be used by police for riot control even when tear gas is used.
Dispensing large quantities
Backpack dispensers for riot control agents, when the intent is to use a larger quantity than possible with grenades, are one type of device used by organizations that might, for example, need to cover a prison yard. Dispensers are also made for attachment to helicopters; see
CBU-19.
Tactics
The front-line officers in a riot control are often fully armored and carry weapons such as batons, designed to be in direct contact with the crowd. These officers subdue rioters and subsequently allow the less heavily armoured, more mobile officers to make arrests where it is deemed necessary. In face of a greater threat, the riot police will be backed up with other officers equipped with
riot gun
In current usage, a riot gun or less-lethal launcher is a type of firearm used to fire Non-lethal weapon, "non-lethal" or "less-lethal" ammunition for the purpose of suppressing riots or apprehending suspects with minimal harm or risk. Less-leth ...
s to fire
tear gas
Tear gas, also known as a lachrymatory agent or lachrymator (), sometimes colloquially known as "mace" after the Mace (spray), early commercial self-defense spray, is a chemical weapon that stimulates the nerves of the lacrimal gland in the ey ...
,
rubber bullet
Rubber bullets (also called rubber baton rounds) are a type of baton round. Despite the name, rubber bullets typically have either a metal core with a rubber coating, or are a homogeneous admixture with rubber being a minority component. Altho ...
s,
plastic bullet
Plastic bullet can refer to:
* Plastic baton round: a large, blunt, low-velocity projectile fired from a specialized gun, intended as a less-lethal weapon for riot control and an alternative to rubber bullets.
* Plastic bullet: a conventionall ...
s or
"beanbag" rounds.
As a less aggressive step,
mounted police
Mounted police are police who patrol on horseback or camelback. Their day-to-day function is typically picturesque or ceremonial, but they are also employed in crowd control because of their mobile mass and height advantage and increasingly in th ...
may first be sent into the crowd. The might and height offered by the
horse
The horse (''Equus ferus caballus'') is a domesticated, one-toed, hoofed mammal. It belongs to the taxonomic family Equidae and is one of two extant subspecies of ''Equus ferus''. The horse has evolved over the past 45 to 55 mi ...
are combined with its training, allowing an officer to more safely infiltrate a crowd. Usually, when front-facing a riot, officers slowly walk in a line parallel to the riot's front, extending to both its ends, as they noisily and simultaneously march and beat their shields with their batons, to cause fear and psychological effects on the crowd.

In the United Kingdom, usually when large demonstrations take place that are deemed unstable, the
territorial police force
A territorial police force is a police service that is responsible for an area defined by sub-national boundaries, distinguished from other police services which deal with the entire country or a type of crime. In countries organized as federation ...
responsible for the demonstration in that area will usually deploy
Police Support Unit personnel who are trained in riot tactics, along with normal divisional officers. If the demonstration turns violent, police will seal roads and other exits to contain protesters in a single area (known as
kettling
Kettling (also known as containment or corralling) is a police tactic for controlling large crowds during demonstrations or protests. It involves the formation of large cordons of police officers who then move to contain a crowd within a l ...
) to prevent widespread damage and wait until the protesters tire. These tactics were seen during the
2009 G-20 London summit protests and the
2010 student protests in London. Tear gas and other more offensive tactics are used as a last resort. Throughout police will be videoing or photographing protesters for future arrests, "
snatch squad" tactics might also be used where several police officers, usually in protective riot gear, rush forwards, occasionally in flying wedge formation to break through the front of a crowd, with the objective of snatching one or more individuals from a riot that are attempting to control the demonstration at which they are present; the target may be a leader or a speaker, or someone who seems to be leading the crowd. This tactic was used in the
2011 England Riots
A series of riots took place between 6 and 11 August 2011 in cities and towns across England, which saw looting and arson, as well as mass deployment of police and the deaths of five people.
The protests started in Tottenham Hale, London, follo ...
, most notably by
Greater Manchester Police
Greater Manchester Police (GMP) is the territorial police force responsible for law enforcement within the metropolitan county of Greater Manchester in North West England.
, Greater Manchester Police employed 6,866 police officers, 3,524 memb ...
who deployed this tactic in
Manchester city centre
Manchester city centre is the central business district of Manchester, England, within the confines of Great Ancoats Street, A6042 Trinity Way, and A57(M) Mancunian Way, which collectively form an inner ring road. The City Centre ward had a ...
on 9 August 2011.
A more straightforward tactic police may use is a
baton charge
A baton charge is a coordinated tactic for dispersing crowds of people, usually used by police, paramilitary or military in response to public disorder. In the Indian subcontinent, a long bamboo stick, called a '' lathi'' in Bengali, Hindi, ...
which involves police officers charging at a crowd of people with batons and in some cases, riot shields. They run at the crowd hitting people with their batons, and in some situations use riot shields to push them away. Baton charging is designed to cause the maximum amount of
pain
Pain is a distressing feeling often caused by intense or damaging Stimulus (physiology), stimuli. The International Association for the Study of Pain defines pain as "an unpleasant sense, sensory and emotional experience associated with, or res ...
, in the hope that they would be compelled to move away from the scene, dispersing the crowd.
Consequences
There has been public controversy when it has come to the tactics of riot control. Moral and legal questions have emerged regarding constitutional rights such as the right to assembly as well as free speech. This form of state violence is also controversial as discussions have emerged regarding the legitimacy as well as the ethics of containing protests. There are discussions on the implications of the perceived military-civilian split. For example, the United States regards its police as civilians. However, the ambiguity of the laws allows for the police to act as military in conflicts with U.S. citizens which has typically been seen as legitimate or at least legal.
There are also legitimate health and safety concerns. Some effects of riot agents include irritation, runny nose, chest tightness, coughing as well as swelling. Long term effects include blindness and respiratory failure. Death can also occur instantly due to chemical burns and respiratory failure. Different countries use different methods of riot control. Chloroacetophenone, chlorobenzylidene malononitrile (tear gas) and dibenzoxazepine are common ingredients for riot control. These are highly toxic and cancerous. Countries often have different standards for usage of chemicals like capsaicin (pepper spray) and who is allowed to own and use these chemicals for self-defense. Some scholars have called for natural alternatives to limit long term health effects like those found in the Capsicum genus and the Zingiber genus.
Psychological toll on protesters and Police officers
As protests and riots rage on throughout the world, there is an ongoing concern that riot control is having an impact on individuals' mental health. This rise in protests has caused an inevitable increase in law-enforcement violence, which has profound impacts on the mental health of protesters and police officers, including
PTSD
Post-traumatic stress disorder (PTSD) is a mental disorder that develops from experiencing a traumatic event, such as sexual assault, domestic violence, child abuse, warfare and its associated traumas, natural disaster, traffic collision, ...
, anxiety, and depression. Studies have shown that rubber bullets, water cannons, and tear gas cause not only problems like eye irritation and external and internal injuries, but can also cause individuals to develop psychological issues. This all comes after the American Public Health Association named police violence as a "public health issue," making it crucial to study the psychological effects caused by riots.
The Hong Kong anti-extradition bill protests are an example that has been studied due to its psychological health effects, stemming from the severe nature of the police response. During these protests in Hong Kong, the police reportedly used upwards of 16,000 canisters of tear gas on these protesters. A survey of the Hong Kong protesters found that 25.7% of the population experienced depression, while 9.1% had thoughts of committing suicide. There were similar findings during the
Arab Spring
The Arab Spring () was a series of Nonviolent resistance, anti-government protests, Rebellion, uprisings, and Insurgency, armed rebellions that spread across much of the Arab world in the early 2010s. It began Tunisian revolution, in Tunisia ...
in Egypt, where school children in schools near the Tahrir Square (the location of massive riots) were experiencing higher rates of depression. In France, it was found that
Yellow Vest protesters who encountered police violence had a 1.54% higher likelihood of experiencing severe depressive symptoms and were 2.58 times more likely to exhibit signs indicative of PTSD. In the whole scheme of police violence towards protesters, it is said that people who were involved in or just living in areas affected by riots could experience an uptick in PTSD by 4% to 41%.
Risk factors that can exacerbate mental health issues from riots:
* Lower socioeconomic status
* Female sex
* Prior exposure to violence
* Excessive social media use
* Lack of support from family and friends
* Ongoing personal conflicts
Psychological Effects on Police Officers
When considering the psychological effects of riot control, it is important to also examine how police officers are impacted by riots. They are exposed to some of the same risks and challenges, such as having objects thrown at them, being physically assaulted, and being exposed to
RCA’s. Even without considering riots, police officers already have almost double the risk of developing PTSD, depression, and anxiety than the average person. When working the frontline of a riot is added, these numbers are bound to go up. For example, during the unrest after the murders of
George Floyd
George Perry Floyd Jr. (October 14, 1973 – May 25, 2020) was an African-American man who was murdered by a white police officer in Minneapolis, Minnesota, during an arrest made after a store clerk suspected Floyd had used a counterfeit tw ...
and
Breonna Taylor
Breonna Taylor (June 5, 1993 – March 13, 2020) was an African-American woman who Killing of Breonna Taylor, was shot and killed while unarmed in her Louisville, Kentucky home by three police officers who entered under the auspices of a No-kn ...
, the number of recorded cases of PTSD among police officers increased upwards of 30%. With the increase in mental illness from the civil unrest and public scrutiny, many police officers resigned, resorted to substance abuse, and even suicide.
Symptoms that Police Officers may face after riots:
* Increased heart rate
* Nervousness or restlessness
* Trembling
* Sweating
* Reduced Appetite
* Anxiety or restlessness
* Frequent or recurrent thoughts of death
January 6th Riots
On the
6th, January 2021, protestors stormed the Capitol Building in Washington D.C. In the process, they beat, trampled and sprayed police officers with chemicals, overwhelmed the police, and almost killed numerous police officers who attempted to stop them from entering the Capitol. In response to this event, members of the Capitol Police and Metropolitan Police Department suffered from PTSD, anxiety, and depression.
Police Officers Bobby Tabron and DeDivine K. Carter of the Metropolitan Police Department filed a lawsuit against former President,
Donald J. Trump - stating that by inciting the mob, Donald Trump caused them "severe injuries" and great "emotional distress."
Both officers claimed to suffer from recurrent dreams and thoughts of the attack on the Capitol Building. Beyond this lawsuit, multiple police officers who responded to the Capitol committed suicide in the following months:
* Metropolitan Police Officer Gunther Hashida
* Metropolitan Police Officer Kyle DeFreytag
* Capitol Police Officer
Howard Liebengood
* Metropolitan Police Officer
Jeffrey Smith
Research

Research into weapons that are more effective for riot control continues.
Netguns are non-lethal weapons designed to fire a
net which entangles the target. Netguns have a long history of being used to capture wildlife, without injury, for research purposes. A netgun is currently in development for
non-lethal
Non-lethal weapons, also called nonlethal weapons, less-lethal weapons, less-than-lethal weapons, non-deadly weapons, compliance weapons, or pain-inducing weapons are weapons intended to be less likely to kill a living target than convention ...
riot control.
Pepper-spray projectile
A pepper-spray projectile, also called a pepper-spray ball, pepper-ball, pepper bomb, or pepper-spray pellet, is a Frangibility, frangible projectile containing a powdered chemical that irritates the eyes and nose in a manner similar to pepper sp ...
launchers are
projectile
A projectile is an object that is propelled by the application of an external force and then moves freely under the influence of gravity and air resistance. Although any objects in motion through space are projectiles, they are commonly found ...
weapon
A weapon, arm, or armament is any implement or device that is used to deter, threaten, inflict physical damage, harm, or kill. Weapons are used to increase the efficacy and efficiency of activities such as hunting, crime (e.g., murder), law ...
s that launch a fragile ball which breaks upon impact and releases an irritant powder called
PAVA (capsaicin II) pepper. The launchers are often slightly modified .68
caliber
In guns, particularly firearms, but not #As a measurement of length, artillery, where a different definition may apply, caliber (or calibre; sometimes abbreviated as "cal") is the specified nominal internal diameter of the gun barrel Gauge ( ...
paintball
Paintball is a competitive sport, competitive team sport, team shooting sport in which players eliminate opponents from play by hitting them with spherical dye-filled gelatin capsules called Paintball equipment#Paintballs, paintballs that b ...
guns.
Stink bomb
A stink bomb, sometimes called a stinkpot, is a device designed to create an unpleasant smell. They range in effectiveness from being used as simple pranks to military grade malodorants or riot control chemical agents.
History
A stink bomb ...
s are devices designed to create an extremely unpleasant
smell for riot control and
area denial
An area denial weapon is a war offensive and Defensive fighting position, defensive and device used to prevent an adversary from occupying or traversing an area of land, sea or air. The specific method may not be totally effective in preventing ...
purposes. Stink bombs are believed to be less dangerous than other riot control chemicals, since they are effective at low concentrations.
Sticky foam weapons are being tested, which cover and immobilize rioters with a gooey foam.
Low frequency
Low frequency (LF) is the ITU designation for radio frequencies (RF) in the range of 30–300 kHz. Since its wavelengths range from 10–1 km, respectively, it is also known as the kilometre band or kilometre waves.
LF radio waves ...
sound cannon
A long-range acoustic device (LRAD), acoustic hailing device (AHD) or sound cannon is a specialized loudspeaker that produces sound at high power for communicating at a distance. It has been used as a method of crowd control, which has caused ...
s are weapons of various types that use sound to injure or incapacitate subjects using a focused beam of
sound
In physics, sound is a vibration that propagates as an acoustic wave through a transmission medium such as a gas, liquid or solid.
In human physiology and psychology, sound is the ''reception'' of such waves and their ''perception'' by the br ...
or
infrasound
Infrasound, sometimes referred to as low frequency sound or incorrectly subsonic (subsonic being a descriptor for "less than the speed of sound"), describes sound waves with a Audio frequency, frequency below the lower limit of human audibility ...
.
Active denial system
The Active Denial System (ADS) is a directed-energy weapon developed by the United States armed forces, U.S. military, designed for area denial, perimeter security and crowd control. Informally, the weapon is also called the heat ray since it wo ...
s (ADS) are a
non-lethal
Non-lethal weapons, also called nonlethal weapons, less-lethal weapons, less-than-lethal weapons, non-deadly weapons, compliance weapons, or pain-inducing weapons are weapons intended to be less likely to kill a living target than convention ...
,
directed-energy weapon
A directed-energy weapon (DEW) is a ranged weapon that damages its target with highly focused energy without a solid projectile, including lasers, microwaves, particle beams, and sound beams. Potential applications of this technology include ...
developed by the
U.S. military
The United States Armed Forces are the military forces of the United States. U.S. federal law names six armed forces: the Army, Marine Corps, Navy, Air Force, Space Force, and the Coast Guard. Since 1949, all of the armed forces, except th ...
. The ADS directs
electromagnetic radiation
In physics, electromagnetic radiation (EMR) is a self-propagating wave of the electromagnetic field that carries momentum and radiant energy through space. It encompasses a broad spectrum, classified by frequency or its inverse, wavelength ...
, specifically, high-frequency microwave radiation, at a frequency of 95
GHz
The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), often described as being equivalent to one event (or Cycle per second, cycle) per second. The hertz is an SI derived unit whose formal expression in ter ...
, which causes the water in the upper epidermis to boil, stimulating a "burning" sensation in the nerve endings and generating intense pain.
Dazzler lasers are
directed-energy weapon
A directed-energy weapon (DEW) is a ranged weapon that damages its target with highly focused energy without a solid projectile, including lasers, microwaves, particle beams, and sound beams. Potential applications of this technology include ...
s that use intense light to cause temporary
blindness
Visual or vision impairment (VI or VIP) is the partial or total inability of visual perception. In the absence of treatment such as corrective eyewear, assistive devices, and medical treatment, visual impairment may cause the individual difficul ...
or disorientation of rioters.
See also
*
*
*
*
*
*
*
*
*
*
*
Riot control units
*
Garda Public Order Unit
The Garda Public Order Unit – commonly known as the ''Garda Riot Squad'' – is a unit of the Garda Síochána, Republic of Ireland, Ireland's police force, that deals with public disorder, including riots and protests.
Staffing and training
A ...
(Ireland)
*
Units for the Reinstatement of Order (Greece)
*
Rapid Action Force (India)
*
Mobile Brigade Corps
The Mobile Brigade Corps () abbreviated Brimob is the SWAT, special operations, paramilitary, and Police tactical unit, tactical unit of the Indonesian National Police (Polri). It is one of the oldest existing units within Polri. Some of its ma ...
(Indonesia)
*
Compagnies Républicaines de Sécurité (France)
*
Mobile Gendarmerie
The Mobile Gendarmerie () (GM) is a subdivision of the French National Gendarmerie whose main mission is to maintain public order (from crowd control to riot control) and general security. Contrary to the Departmental Gendarmerie, whose jurisdic ...
(France)
*
Police Tactical Unit
A police tactical unit (PTU) is a specialized police unit trained and equipped to handle situations that are beyond the capabilities of ordinary law enforcement units because of the level of violence (or risk of violence) involved. The tasks of a ...
(Hong Kong)
**
Special Tactical Squad (Hong Kong)
*
Territorial Support Group
The Territorial Support Group (TSG) is a Met Operations unit of London's Metropolitan Police Service (MPS) which focuses on public order policing and other specialist areas. In 2012 it consisted of 793 officers and 29 support staff. The TSG ...
(London in England)
*
Carabinieri Mobile Units Division (Italy)
*
Mobile Unit (Italy)
In Italy, the Mobile Units () of the Polizia di Stato, often generically identified as a "''Celere Units''", are the police units used as a ready-to-use resource for riot control and for intervention in areas affected by disasters.
Currently ther ...
*
Riot Police Unit (Japan)
* (Spain)
*
Çevik Kuvvet (Turkey)
Weapons used in riot control
*
Non-lethal weapon
Non-lethal weapons, also called nonlethal weapons, less-lethal weapons, less-than-lethal weapons, non-deadly weapons, compliance weapons, or pain-inducing weapons are weapons intended to be less likely to kill a living target than convention ...
**
CS gas
The compound 2-chlorobenzalmalononitrile (also called ''o''-chlorobenzylidene malononitrile; chemical formula: C10H5ClN2), a cyanocarbon, is the defining component of the lachrymatory agent commonly referred to as CS gas, a tear gas which ...
**
Long Range Acoustic Device
**
Plastic bullets
Plastic bullet can refer to:
* Plastic baton round: a large, blunt, low-velocity projectile fired from a specialized gun, intended as a less-lethal weapon for riot control and an alternative to rubber bullets.
* Plastic bullet: a conventionally ...
**
Pepper spray
Pepper spray, oleoresin capsicum spray, OC spray, capsaicin spray, mace, or capsicum spray is a Tear gas, lachrymator (tear gas) product containing as its active ingredient the chemical compound capsaicin, which irritates the eyes with burning ...
**
Rubber bullet
Rubber bullets (also called rubber baton rounds) are a type of baton round. Despite the name, rubber bullets typically have either a metal core with a rubber coating, or are a homogeneous admixture with rubber being a minority component. Altho ...
**
Water cannon
A water cannon is a device that shoots a high-velocity stream of water. Typically, a water cannon can deliver a large volume of water, often over dozens of meters. They are used in firefighting, large vehicle washing, riot control, and mining. ...
**
Pellet guns (pellet shotguns)
*
Use of bayonets for crowd control
Notes
References
External links
*
{{DEFAULTSORT:Riot Control