Mass shooting


A mass shooting is a violent crime in which one or more attackers use a firearm to kill or injure multiple individuals in rapid succession. Mass shootings with multiple deceased victims are a form of mass murder. There is no widely accepted specific definition of the term, and different organizations tracking such incidents use different criteria. Mass shootings are characterized by the targeting, often indiscriminate, of victims outside a combat setting, and the term generally excludes gang violence, shootouts, domestic violence and self-defense. The perpetrator of an ongoing mass shooting may be referred to as an active shooter.
Mass shootings may be done for personal or psychological reasons, such as by individuals who are deeply disgruntled, seeking notoriety, or are intensely angry at a perceived grievance; though they have also been used as a terrorist tactic, such as when members of an ethnic or religious group are deliberately targeted. It has been theorized that media coverage of mass shootings has contributed to later shooters being motivated by fame-seeking. After mass shootings, mental health issues such as survivor's guilt and post-traumatic stress disorder are commonly suffered by survivors, first responders, and victims' loved ones.
The number of people killed in mass shootings is difficult to determine due to the lack of a commonly agreed upon definition. In the United States—the country with the most mass shootings—there were 103 deaths in mass shootings in 2021 using the FBI's definition, and 706 deaths using the Gun Violence Archive's definition. Mass shootings are relatively rare in China, Singapore, South Korea, Japan, the United Kingdom, Russia, and across Africa.
Mass shootings perpetrated with legally purchased firearms often prompt scrutiny of and changes to local gun laws. For example, mass shootings in Dunblane, Port Arthur and Christchurch respectively contributed to significant expansions of firearm restrictions in the United Kingdom, Australia and New Zealand.

Definitions

There are a variety of definitions of a mass shooting:
  • Mass Shooting Tracker, a crowdsourced data site cited by CNN, MSNBC, The New York Times, The Washington Post, The Economist, the BBC, etc., defines a mass shooting as any incident in which four or more people are shot, whether injured or killed.
  • CBS defines a mass shooting as an event involving the shooting of five or more people with no cooling-off period.
  • Mother Jones defines a mass shooting as an indiscriminate rampage in a public place, resulting in three or more victims killed by the attacker, excluding gang violence, armed robbery, and attacks by unidentified perpetrators.
  • Crime violence research group Gun Violence Archive, whose research is used by major American media outlets, defines a mass shooting as having a "minimum of four victims shot, either injured or killed, not including any shooter who may also have been killed or injured in the incident," differentiating between a mass shooting and mass murder and not counting shooters as victims.
  • Media outlets such as CNN, and some crime violence research groups such as the Gun Violence Archive, define mass shootings as involving "four or more shot in a single incident, at the same general time and location, not including the shooter".
  • A Congressional Research Service report from 2013 specifies that a public mass shooting involves four or more killings on indiscriminate victims, while excluding violence committed as a means to an end, such as robbery or terrorism.
  • An Australian study from 2006 specifies five individuals killed.
There are also different definitions of the term mass killing:
  • Under U.S. federal law, the Attorney General – on a request from a state – may assist in investigating "mass killings", rather than mass shootings. The term is defined as the murder of four or more people with no cooling-off period, but was redefined by Congress in 2013 as being the murder of three or more people.
  • In "Behind the Bloodshed", a report by USA Today, a mass killing is defined as any incident in which four or more were killed, including familial killings. This definition is also used by the Washington Post.
  • According to the Investigative Assistance for Violent Crimes Act of 2012, signed into law in January 2013, a mass killing is defined as a killing with at least three deaths, excluding the perpetrator.
An act of mass shooting is typically defined as terrorist when it "appears to have been intended" to intimidate or to coerce people; although a mass shooting is not necessarily an act of terrorism solely by itself.
The lack of a single definition can lead to alarmism in the news media, with some reports conflating categories of different crimes.
The perpetrator is typically but not always excluded from the body count.

Prevalence

The number of people killed in mass shootings is difficult to determine due to the lack of a commonly agreed definition. It is also difficult to determine whether their frequency is increasing or decreasing over time, for the same reason. In addition, there is a large impact from random chance, outliers, and the specific time frame chosen for analysis.

United States

The United States has had the most mass shootings of any country in the world. There were 103 deaths in mass shootings in 2021 using the FBI's definition, and 706 deaths using the Gun Violence Archive's definition. The FBI's definition refers to "active shooter incidents" defined as "one or more individuals actively engaged in killing or attempting to kill people in a populated area", while the Gun Violence Archive's definition counts incidents where at least four people were shot, but not necessarily killed.
In a 2016 study published by criminologist Adam Lankford, it was estimated that 31 percent of all public mass shooters from 1966 to 2012 attacked in the United States, although the U.S. had less than five percent of the world's population. The study concludes that "The United States and other nations with high firearm ownership rates may be particularly susceptible to future public mass shootings, even if they are relatively peaceful or mentally healthy according to other national indicators."
Criminologist Gary Kleck criticized Lankford's findings, stating the study merely shows a proportional relationship but fails to prove that gun ownership causes mass shootings. The backlash from economist and gun rights advocate John Lott also raised objections to Lankford's methodology and refusal to share his data. He speculated that Lankford had overlooked a significant number of mass shootings outside the U.S., which if accounted for would adjust the nation's share closer to 2.88 percent; slightly below the world average. Lankford has since followed up on his research, publishing his data and clarifying that the United States from 1998 to 2012 did have more than six times its global share of public mass shooters who attacked alone, which is almost always the case with mass shooters. Using the data from Lott and Moody's 2019 study of mass shootings, Lankford explains that "41 of all 138 public mass shootings by single perpetrators worldwide were committed in the United States. That represents 29.7 percent. Because America had in those years approximately 4.5 percent of the world's population, this indicates that based on their data, the United States had more than six times its global share of public mass shooters who attacked alone. In a subsequent study, Lankford criticized Lott and Moody for including "attacks by terrorist organizations, genocidal militias, armed rebel groups, and paramilitary fighters" in their data and suggested they "misrepresent approximately 1,000 foreign cases from their own dataset" in other ways.
Mass shootings have also been observed to be followed by an increase in the purchase of weapons, but this does not seem to create an increased feeling of needing guns in either gun owners or non-owners.
Even though the global COVID-19 pandemic reduced public gatherings from March 2020 onward, the number of mass shootings increased significantly over that period. It "even doubled in July 2020 compared to a year earlier".

Other countries

  • Mass shootings are exceedingly rare in China, Singapore, South Korea, Japan and the United Kingdom. China's strict gun control laws have prohibited private ownership of firearms since 1951. Japan has as few as two gun-related homicides per year. These numbers include all homicides in the country, not just mass shootings.
  • While gun violence is relatively uncommon in India due to strict gun control laws, incidents of mass shootings continue to occur.
  • Mass shootings are relatively rare in Russia, but they have occurred sporadically over the past decade. Most of the incidents involve lone gunmen, although there have been a few cases involving multiple shooters.
  • Mass shootings have become a common occurrence in Mexico, particularly in recent years. The country has been plagued by violence from drug cartels, which have been responsible for many of the deadliest mass shootings in Mexico's history.
  • Brazil has one of the highest rates of gun violence in the world, and mass shootings have become more common in recent years. In 2022, there were at least 10 mass shootings in Brazil, resulting in the deaths of over 50 people. Furthermore, In 2017, there were over 45,000 gun-related homicides countrywide.
  • In Africa, whilst incidents of mass violence resulting from terrorism and ethnic conflict have occurred, mass shootings are generally understood as rare.

    Victims and survivors

It is common for mass shooting survivors to suffer from post-traumatic stress disorder and survivors guilt. In 2019, Sydney Aiello and Calvin Desir, both survivors of the Parkland high school shooting, committed suicide as a result of survivors guilt; Aiello knew of a friend killed in the shooting.
After mass shootings, survivors frequently report persistent mental health effects; population-based and survivor studies have found elevated major depression and post-traumatic stress disorder, particularly among those with higher exposure and limited social support. In addition, studies have evaluated post-incident service use, noting variable awareness and uptake of mental health and other support services among affected communities. A survivor of the Knoxville Unitarian Universalist church shooting wrote about his reaction to other mass shooting incidents. The father of a victim in a mass shooting at a movie theater in Aurora, Colorado, wrote about witnessing other mass shootings after the loss of his son. The survivors of the 2011 Norway attacks recounted their experience to GQ magazine. In addition, one paper studied Swedish police officers' reactions to a mass shooting.