Mass murder is the

violent crime A violent crime, violent felony, crime of violence or crime of a violent nature is a crime in which an offender or perpetrator uses or threatens to use harmful Force (law), force upon a victim. This entails both crimes in which the violence, vio ...

kill Kill often refers to: *Homicide, one human killing another *cause death, to kill a living organism, to cause its death Other common uses include: *Kill (body of water), a body of water, most commonly a creek *Kill (command), a computing command *K ...

ing a number of people, typically simultaneously or over a relatively short period of time and in close geographic proximity. A mass murder typically occurs in a single location where one or more persons kill several others. 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 ...

Congress A congress is a formal meeting of the representatives of different countries, constituent states, organizations, trade unions, political parties, or other groups. The term originated in Late Middle English to denote an encounter (meeting of ...

defined mass murders as the killing of three or more persons during an event with no "cooling-off period" between the homicides. The

Investigative Assistance for Violent Crimes Act Investigative Assistance for Violent Crimes Act of 2012 (IAVCA) is a federal law in the United States that clarifies the statutory authority for federal law enforcement agencies to provide investigatory assistance to the States. The Act provid ...

of 2012, passed in the aftermath of the

Sandy Hook Elementary School shooting On December 14, 2012, a mass shooting occurred at Newtown Public Schools, Sandy Hook Elementary School in Newtown, Connecticut, United States. The perpetrator, 20-year-old Adam Lanza, shot and killed 26 people. The victims were 20 children bet ...

, clarified the statutory authority for federal law enforcement agencies, including those in the Departments of

Justice In its broadest sense, justice is the idea that individuals should be treated fairly. According to the ''Stanford Encyclopedia of Philosophy'', the most plausible candidate for a core definition comes from the ''Institutes (Justinian), Inst ...

and

Homeland Security Homeland security is an American national security term for "the national effort to ensure a homeland that is safe, secure, and resilient against terrorism and other hazards where American interests, aspirations, and ways of life can thrive" to ...

, to assist state law enforcement agencies, and mandated across federal agencies a definition of "mass killing" as three or more killings during an incident. A mass murder may be further classified as a

mass shooting A mass shooting is a violent crime in which one or more attackers use a firearm to Gun violence, kill or injure multiple individuals in rapid succession. There is no widely accepted specific definition, and different organizations tracking su ...

or a

mass stabbing A mass stabbing is a single incident in which multiple victims are injured or killed with a sharp object thrusted at the victims, piercing through the skin and injuring the victims. Examples of sharp instruments used in mass stabbings may includ ...

. Mass murderers differ from

spree killers A spree killer is someone who commits a criminal act that involves two or more murders in a short time, often in multiple locations. There are different opinions about what durations of time a killing spree may take place in. The United States ...

, who kill at two or more locations with almost no time break between murders and are not defined by the number of victims, and

serial killer A serial killer (also called a serial murderer) is a person who murders three or more people,An offender can be anyone: * * * * * (This source only requires two people) with the killings taking place over a significant period of time in separat ...

s, who kill people over long periods of time.

By terrorist organizations

Many terrorist groups in recent times have used the tactic of killing many victims to fulfill their political aims. Such incidents have included: * 33 civilians killed in the Başbağlar attack by the PKK on July 5, 1993; * 19 American airmen killed in the

Khobar Towers bombing The Khobar Towers bombing was an attack on part of a housing complex in the city of Khobar, Saudi Arabia, near the national oil company (Saudi Aramco) headquarters of Dhahran and nearby King Abdulaziz Air Base on 25 June 1996. At that time, Khob ...

on June 25, 1996, by Hezbollah Al-Hejaz; * 2,977 people killed by

al-Qaeda , image = Flag of Jihad.svg , caption = Jihadist flag, Flag used by various al-Qaeda factions , founder = Osama bin Laden{{Assassinated, Killing of Osama bin Laden , leaders = {{Plainlist, * Osama bin Lad ...

in the

September 11 attacks The September 11 attacks, also known as 9/11, were four coordinated Islamist terrorist suicide attacks by al-Qaeda against the United States in 2001. Nineteen terrorists hijacked four commercial airliners, crashing the first two into ...

of 2001; * 193 people killed in the

2004 Madrid train bombings The 2004 Madrid train bombings (also known in Spain as 11M) were a series of coordinated, nearly simultaneous bombings against the Cercanías commuter train system of Madrid, Spain, on the morning of 11 March 2004—three days before Spain's ...

by al-Qaeda; * 334 (including 186 children) killed in the

Beslan school siege The Beslan school siege, also referred to as the Beslan school hostage crisis or the Beslan massacre, was an Islamic terrorism, Islamic terrorist attack that started on 1 September 2004. It lasted three days, and involved the imprisonment of mo ...

on September 1–4, 2004 by Riyad-us Saliheen; * 52 killed in the

2005 London bombings The 7 July 2005 London bombings, also referred to as 7/7, were a series of four co-ordinated suicide attacks carried out by Islamist terrorists that targeted commuters travelling on London's public transport during the morning rush hour. ...

Islamic terrorists Islamic terrorism (also known as Islamist terrorism, radical Islamic terrorism, or jihadist terrorism) refers to terrorist acts carried out by fundamentalist militant Islamists and Islamic extremists. Since at least the 1990s, Islamist ...

; * 166 killed in the

2008 Mumbai attacks The 2008 Mumbai attacks, also referred to as 26/11 attacks, were a series of coordinated Islamic terrorism, Islamist terrorist attacks that took place in November 2008, when 10 members of Lashkar-e-Taiba, a Pakistan-based Islamist terrorist o ...

Lashkar-e-Taiba Lashkar-e-Taiba (LeT) is a Pakistani Islamism, Islamist militant organization driven by a Salafi jihadism, Salafi jihadist ideology. The organisation's primary stated objective is to merge the whole of Kashmir with Pakistan. It was founded in 19 ...

; * 156 children and teachers killed in the

2014 Peshawar school massacre On 16 December 2014, six gunmen affiliated with the Tehrik-i-Taliban Pakistan (TTP) conducted a terrorist attack on the Army Public School in the northwestern Pakistani city of Peshawar. The terrorists, all of whom were foreign nationals, com ...

by Tehrik-i-Taliban in

Peshawar Peshawar is the capital and List of cities in Khyber Pakhtunkhwa by population, largest city of the Administrative units of Pakistan, Pakistani province of Khyber Pakhtunkhwa. It is the sixth most populous city of Pakistan, with a district p ...

, Pakistan; * 1,095 killed in the

Camp Speicher massacre On 12 June 2014, the Islamic State (IS) summarily executed between 1,095 and 1,700 Iraqi cadets near Tikrit. The killings took place during IS's Northern Iraq offensive, when the cadets were captured outside of Camp Speicher during their at ...

by the

Islamic State The Islamic State (IS), also known as the Islamic State of Iraq and the Levant (ISIL), the Islamic State of Iraq and Syria (ISIS) and Daesh, is a transnational Salafi jihadism, Salafi jihadist organization and unrecognized quasi-state. IS ...

; * 224 people killed in the

Metrojet Flight 9268 Metrojet Flight 9268 was an international chartered passenger flight operated by Russian airline Kogalymavia (branded as Metrojet). On 31 October 2015, at 06:13 local time EST (04:13 UTC), the Airbus A321-231 operating the flight exploded ...

by the

; * 130 killed as the result of the

November 2015 Paris attacks A series of coordinated Islamist terrorist attacks took place on Friday, 13 November 2015 in Paris, France, and the city's northern suburb, Saint-Denis. Beginning at 21:16, three suicide bombers struck outside the Stade de France in Saint-De ...

by the Islamic State; * 1,163 killed in the

2023 Hamas-led attack on Israel On October 7, 2023, Hamas and several other Palestinians, Palestinian militant groups launched coordinated armed incursions from the Gaza Strip into the Gaza envelope of southern Israel, the first invasion of Israeli territory since the 1948 ...

Hamas The Islamic Resistance Movement, abbreviated Hamas (the Arabic acronym from ), is a Palestinian nationalist Sunni Islam, Sunni Islamism, Islamist political organisation with a military wing, the Qassam Brigades. It has Gaza Strip under Hama ...

and several other

Palestinian Palestinians () are an Arab ethnonational group native to the Levantine region of Palestine. *: "Palestine was part of the first wave of conquest following Muhammad's death in 632 CE; Jerusalem fell to the Caliph Umar in 638. The indigenous p ...

Terrorist groups;

By cults

Certain

cult Cults are social groups which have unusual, and often extreme, religious, spiritual, or philosophical beliefs and rituals. Extreme devotion to a particular person, object, or goal is another characteristic often ascribed to cults. The term ...

s, especially religious cults, have committed a number of mass killings and mass

murder–suicide A murder–suicide is an act where an individual intentionally kills one or more people before killing themselves. The combination of murder and suicide can take various forms: * Suicide after or during murder inflicted on others ** Suicide af ...

s. *

Jim Jones James Warren Jones (May 13, 1931 – November 18, 1978) was an American cult leader, preacher and mass murderer who founded and led the Peoples Temple between 1955 and 1978. Jones and the members of his inner circle planned and orchestrat ...

Peoples Temple The Peoples Temple of the Disciples of Christ, originally Peoples Temple Full Gospel Church and commonly shortened to Peoples Temple, was an American new religious organization which existed between 1954 and 1978 and was affiliated with the C ...

Jonestown The Peoples Temple Agricultural Project, better known by its informal name "Jonestown", was a remote settlement in Guyana established by the Peoples Temple, an American religious movement under the leadership of Jim Jones. Jonestown became in ...

, Guyana, where 919 people died in 1978 *

Order of the Solar Temple The Order of the Solar Temple (, OTS), or simply the Solar Temple, was a new religious movement and secret society, often described as a cult, notorious for the mass deaths of many of its members in several mass murders and suicides throughout ...

in Canada, Switzerland, and France, where 74 died in

1994 The year 1994 was designated as the " International Year of the Family" and the "International Year of Sport and the Olympic Ideal" by the United Nations. In the Line Islands and Phoenix Islands of Kiribati, 1994 had only 364 days, omitti ...

1995 1995 was designated as: * United Nations Year for Tolerance * World Year of Peoples' Commemoration of the Victims of the Second World War This was the first year that the Internet was entirely privatized, with the United States government ...

, and

1997 Events January * January 1 – The Emergency Alert System is introduced in the United States. * January 11 – Turkey threatens Cyprus on account of a deal to buy Russian S-300 missiles, prompting the Cypriot Missile Crisis. * January 1 ...

Shoko Asahara , born , was a Japanese cult leader and terrorist who founded and led the doomsday cult known as Aum Shinrikyo. He was convicted of masterminding the 1995 sarin gas attack on the Tokyo subway, and was also involved in several other crimes. As ...

Aum Shinrikyo , better known by their former name , is a Japanese new religions, Japanese new religious movement and doomsday cult founded by Shoko Asahara in 1987. It carried out the deadly Tokyo subway sarin attack in 1995 and was found to have been respo ...

, which killed 14 in

Tokyo Tokyo, officially the Tokyo Metropolis, is the capital of Japan, capital and List of cities in Japan, most populous city in Japan. With a population of over 14 million in the city proper in 2023, it is List of largest cities, one of the most ...

, Japan, in 1995 *

Movement for the Restoration of the Ten Commandments of God The Movement for the Restoration of the Ten Commandments of God (MRTC or MRTCG) was a religious movement founded by Credonia Mwerinde and Joseph Kibweteere in southwestern Uganda, notorious for the mass death of several hundred members of the ...

in Uganda, where 778 died in 2000

By individuals and governments

Mass murderers may be categorized into killers of family, of coworkers, of students, and of random strangers. Their motives vary. One motivation for mass murder is

revenge Revenge is defined as committing a harmful action against a person or group in response to a grievance, be it real or perceived. Vengeful forms of justice, such as primitive justice or retributive justice, are often differentiated from more fo ...

, but other motivations are possible, including the need for attention or fame. Several

autocratic Autocracy is a form of government in which absolute power is held by the head of state and Head of government, government, known as an autocrat. It includes some forms of monarchy and all forms of dictatorship, while it is contrasted with demo ...

regimes have been known to have ordered mass murders including

genocide Genocide is violence that targets individuals because of their membership of a group and aims at the destruction of a people. Raphael Lemkin, who first coined the term, defined genocide as "the destruction of a nation or of an ethnic group" by ...

and

politicide Political cleansing of a population is the elimination of categories of people in specific areas for political reasons. The means may vary and include forced migration, ethnic cleansing and population transfers. Genocide Convention Under the G ...

. Acting on the orders of Soviet leader

Joseph Stalin Joseph Vissarionovich Stalin (born Dzhugashvili; 5 March 1953) was a Soviet politician and revolutionary who led the Soviet Union from 1924 until Death and state funeral of Joseph Stalin, his death in 1953. He held power as General Secret ...

, Vasili Blokhin's

war crime A war crime is a violation of the laws of war that gives rise to individual criminal responsibility for actions by combatants in action, such as intentionally killing civilians or intentionally killing prisoners of war, torture, taking hostage ...

of killing of 7,000 Polish prisoners of war, shot over 28 days, was one of the most organized and protracted mass murders by a single individual on record.

Law enforcement response and countermeasures

Analysis of the

Columbine High School massacre A school shooting and attempted bombing occurred on April 20, 1999, at Columbine High School in Columbine, Colorado, United States. The perpetrators, twelfth-grade students Eric Harris and Dylan Klebold, murdered 13 students and one teach ...

and other incidents where

law enforcement officer A law enforcement officer (LEO), or police officer or peace officer in North American English, is a public-sector or private-sector employee whose duties primarily involve the enforcement of laws, protecting life & property, keeping the peace, ...

s waited for backup has resulted in changed recommendations regarding what victims, bystanders, and law enforcement officers should do. In the Columbine shooting, the perpetrators,

Eric Harris and Dylan Klebold Eric David Harris (April 9, 1981 – April 20, 1999) and Dylan Bennet Klebold ( ; September 11, 1981 – April 20, 1999) were American high school seniors and mass murderers who perpetrated the Columbine High School massacre at Columbine ...

, were able to murder 13 people, then commit suicide before the first SWAT team even entered the school. Average response time by law enforcement to a mass shooting is typically much longer than the time the shooter is engaged in killing. While immediate action may be extremely dangerous, it could save lives which would be lost if victims and bystanders involved in the situation remain passive, or law enforcement response is delayed until overwhelming force can be deployed. It is recommended that victims and bystanders involved in the incident take active steps to flee, hide, or fight the shooter and that law enforcement officers present or first arriving at the scene attempt immediately to engage the shooter. In many instances, immediate action by victims, bystanders, or law enforcement officers has saved lives. However, law enforcement programs and actions have so far been unable to reduce the total number of incidents. In 2020, a record number of 600 mass shootings occurred.

Criticism as an analytical category

Commentators have pointed out that there are a wide variety of ways that homicides with more than several victims might be classified. Such incidents can be, and have been even in recent decades, classified many different ways including "as a ''mass shooting''; as a ''school shooting''; as ''mass murder''; as ''workplace violence''...; as ''a crime involving an assault rifle''; as ''a case of a mentally ill person committing acts of violence''; and so on." How such rarely occurring incidents of homicide are classified tends to change significantly with time. "In the 1960s and 1970s,... it was understood that the key feature of number of suchcases was a high body count. These early discussions of mass murder lumped together variety ofcases that varied along what would come to be seen as important dimensions: * Time: Did the killings occur more or less simultaneously, or did they extend over several days, months, or years? * Place: Did the killings occur in a single location, or in a variety of places? * Method: How were the victims killed?" In the late decades of the 20th century and early years of the 2000s, the most popular classifications moved to include method, time and place. While such classifications may assist in gaining human meaning, as human-selected categories, they can also carry significant meaning and reflect a particular point of view of the commentator who assigned the descriptor.

References

External links

What makes a Mass Killer?

Mass Murder: A Small Person's Way to Immortality

Mass shootings interactive map

Online Encyclopedia of Mass Violence

by

James Alan Fox James Alan Fox is a Professor of Criminology, Law, and Public Policy and former dean at Northeastern University in Boston, Massachusetts, in the United States. Fox holds a bachelor's degree in sociology (1972), a master's degree in criminology (1 ...

Boston.com ''Boston.com'' is a regional website that offers news and information about the Boston, Massachusetts, area. It is owned and operated by Boston Globe Media Partners, publisher of ''The Boston Globe''. History ''Boston.com'' was one of the firs ...

, January 16, 2011. {{Authority control *

Murder Murder is the unlawful killing of another human without justification (jurisprudence), justification or valid excuse (legal), excuse committed with the necessary Intention (criminal law), intention as defined by the law in a specific jurisd ...