Between 1982 and September 2024, 82 out of the 151 mass shootings in the United States were carried out by White shooters. By comparison, the perpetrator was African American in 26 mass shootings, and Latino in 12. When calculated as percentages, this amounts to 54 percent, 17 percent, and eight percent respectively. Race of mass shooters reflects the U.S. population Broadly speaking, the racial distribution of mass shootings mirrors the racial distribution of the U.S. population as a whole. While a superficial comparison of the statistics seems to suggest African American shooters are over-represented and Latino shooters underrepresented, the fact that the shooter’s race is unclear in around nine percent of cases, along with the different time frames over which these statistics are calculated, means no such conclusions should be drawn. Conversely, looking at the mass shootings in the United States by gender clearly demonstrates that the majority of mass shootings are carried out by men. Mass shootings and mental health With no clear patterns between the socio-economic or cultural background of mass shooters, increasing attention has been placed on mental health. Analysis of the factors Americans considered to be to blame for mass shootings showed 80 percent of people felt the inability of the mental health system to recognize those who pose a danger to others was a significant factor. This concern is not without merit – in over half of the mass shootings since 1982, the shooter showed prior signs of mental health issues, suggesting improved mental health services may help deal with this horrific problem. Mass shootings and guns In the wake of multiple mass shootings, critics have sought to look beyond the issues of shooter identification and their influences by focusing on their access to guns. The majority of mass shootings in the U.S. involve firearms which were obtained legally, reflecting the easy ability of Americans to purchase and carry deadly weapons in public. Gun control takes on a particular significance when the uniquely American phenomenon of school shootings is considered. The annual number of incidents involving firearms at K-12 schools in the U.S. was over 100 in each year since 2018. Conversely, similar incidents in other developed countries exceptionally rare, with only five school shootings in G7 countries other than the U.S. between 2009 and 2018.

From 1966 to January 2024, ** percent of mass public shooters who carried out the shooting at K-12 schools in the United States identified as White, followed by ** percent who were Native American and * percent who were Latinx. For mass public shootings occurring at colleges and universities, the shooter was most likely to identify as Asian, at ** percent, followed by ** percent who were White. In addition, Black and Middle Eastern shooters each made up ** percent. The source defines a mass public shooting as a multiple homicide incident in which 4 or more victims are murdered with firearms—not including the offender(s)—within one event, and at least some of the murders occurred in a public location or locations in close geographical proximity (e.g., a workplace, school, restaurant, or other public settings), and the murders are not attributable to any other underlying criminal activity or commonplace circumstance (armed robbery, criminal competition, insurance fraud, argument, or romantic triangle). Mass shootings attributable to gangs, as well as most domestic homicides, are therefore excluded from this definition.

THIS DATASET WAS LAST UPDATED AT 2:11 PM EASTERN ON JULY 4

OVERVIEW

2019 had the most mass killings since at least the 1970s, according to the Associated Press/USA TODAY/Northeastern University Mass Killings Database.

In all, there were 45 mass killings, defined as when four or more people are killed excluding the perpetrator. Of those, 33 were mass shootings . This summer was especially violent, with three high-profile public mass shootings occurring in the span of just four weeks, leaving 38 killed and 66 injured.

A total of 229 people died in mass killings in 2019.

The AP's analysis found that more than 50% of the incidents were family annihilations, which is similar to prior years. Although they are far less common, the 9 public mass shootings during the year were the most deadly type of mass murder, resulting in 73 people's deaths, not including the assailants.

One-third of the offenders died at the scene of the killing or soon after, half from suicides.

About this Dataset

The Associated Press/USA TODAY/Northeastern University Mass Killings database tracks all U.S. homicides since 2006 involving four or more people killed (not including the offender) over a short period of time (24 hours) regardless of weapon, location, victim-offender relationship or motive. The database includes information on these and other characteristics concerning the incidents, offenders, and victims.

The AP/USA TODAY/Northeastern database represents the most complete tracking of mass murders by the above definition currently available. Other efforts, such as the Gun Violence Archive or Everytown for Gun Safety may include events that do not meet our criteria, but a review of these sites and others indicates that this database contains every event that matches the definition, including some not tracked by other organizations.

This data will be updated periodically and can be used as an ongoing resource to help cover these events.

Using this Dataset

To get basic counts of incidents of mass killings and mass shootings by year nationwide, use these queries:

Mass killings by year

Mass shootings by year

To get these counts just for your state:

Filter killings by state

Definition of "mass murder"

Mass murder is defined as the intentional killing of four or more victims by any means within a 24-hour period, excluding the deaths of unborn children and the offender(s). The standard of four or more dead was initially set by the FBI.

This definition does not exclude cases based on method (e.g., shootings only), type or motivation (e.g., public only), victim-offender relationship (e.g., strangers only), or number of locations (e.g., one). The time frame of 24 hours was chosen to eliminate conflation with spree killers, who kill multiple victims in quick succession in different locations or incidents, and to satisfy the traditional requirement of occurring in a “single incident.”

Offenders who commit mass murder during a spree (before or after committing additional homicides) are included in the database, and all victims within seven days of the mass murder are included in the victim count. Negligent homicides related to driving under the influence or accidental fires are excluded due to the lack of offender intent. Only incidents occurring within the 50 states and Washington D.C. are considered.

Methodology

Project researchers first identified potential incidents using the Federal Bureau of Investigation’s Supplementary Homicide Reports (SHR). Homicide incidents in the SHR were flagged as potential mass murder cases if four or more victims were reported on the same record, and the type of death was murder or non-negligent manslaughter.

Cases were subsequently verified utilizing media accounts, court documents, academic journal articles, books, and local law enforcement records obtained through Freedom of Information Act (FOIA) requests. Each data point was corroborated by multiple sources, which were compiled into a single document to assess the quality of information.

In case(s) of contradiction among sources, official law enforcement or court records were used, when available, followed by the most recent media or academic source.

Case information was subsequently compared with every other known mass murder database to ensure reliability and validity. Incidents listed in the SHR that could not be independently verified were excluded from the database.

Project researchers also conducted extensive searches for incidents not reported in the SHR during the time period, utilizing internet search engines, Lexis-Nexis, and Newspapers.com. Search terms include: [number] dead, [number] killed, [number] slain, [number] murdered, [number] homicide, mass murder, mass shooting, massacre, rampage, family killing, familicide, and arson murder. Offender, victim, and location names were also directly searched when available.

This project started at USA TODAY in 2012.

Contacts

Contact AP Data Editor Justin Myers with questions, suggestions or comments about this dataset at jmyers@ap.org. The Northeastern University researcher working with AP and USA TODAY is Professor James Alan Fox, who can be reached at j.fox@northeastern.edu or 617-416-4400.

Since 1982, an astonishing 145 mass shootings have been carried out in the United States by male shooters. In contrast, only four mass shootings (defined by the source as a single attack in a public place in which four or more victims were killed) have been carried out by women. Gun ownership in the U.S. Possession of firearms in the United States is protected by the 2nd Amendment of the Constitution and has been a defining aspect of American civil liberties since the writing of the Bill of Rights. It is estimated that the United States has the highest rate of civilian-owned firearms in the world, and Americans continually poll against handgun restrictions. Mass shootings However, with high gun ownership comes high responsibility. The United States consistently faces numerous mass shootings each year, particularly in schools. The five deadliest mass shootings have all occurred since 2007, with the deadliest being the Las Vegas Strip massacre in 2017, which claimed the lives of 58 people and injured 546 more.

From 1966 to 2021, the most common background trait of mass shooters in the United States was a criminal record, at 64.5 percent, followed by a history of violence at 62.8 percent. In comparison, gang affiliation was the least common trait of mass shooters, at 1.7 percent.

As of September 4, there were two mass shootings in the United States in 2024. This is compared to one mass shooting in 1982, one in 2000, and 12 mass shootings in 2022 and 2023. School shootings The United States sees the most school shootings in the world. Some motivations for school shootings included depression, seeking revenge, and bullying. As a result of the large amount of school shootings, gun control has become a central topic in U.S. politics. This widespread problem happens across the United States; however California saw the highest number of K-12 school shootings in the United States since 1970. However, the deadliest school shooting (as of October 2023) was the Virginia Tech massacre in 2007. This tragedy left 33 dead and 23 injured. Mass shooting issues Mass shootings happen when there are several injuries or deaths from a firearm-related violence. Throughout the last century, mass shootings have become an epidemic in the United States. However, despite the increase in mass shootings and number of casualties, the U.S. government has done little to prevent future shootings from happening. As a result of the lack of cooperation in politics, mass shootings have become an important issue for Generation Z living in the United States. Furthermore, having the right to bear arms is a popular belief in the U.S. and the percentage of households in the United States owning at least one firearm has remained somewhat steady since 1972.

As of September 4, eight people were killed in mass shootings in the United States in 2024. A total 1,159 victims were fatally injured during mass shootings in the United States between 1982 and September 4, 2024.

When and to what extent do crises and significant events induce changes in political attitudes? Theories of public opinion and policymaking predict that major events restructure public opinion and pry open new political opportunities. We examine the effect of major events on support for public policies in the context of the Sandy Hook Elementary School mass shooting in December 2012 using a nationally representative panel survey of U.S.\ adults. Across both cross-sectional and within-subject analyses, we find no evidence that Americans granted greater support for gun control after the Sandy Hook shooting. Our null findings persist across a range of political and demographic groups. We also find no evidence of attitude polarization as a result of Sandy Hook. Our results suggest that elite polarization in a particular issue area leads citizens to employ motivated reasoning when interpreting critical events, thereby reducing the capacity for attitude change. Our findings have important implications for identifying the conditions under which major events affect support for public policies and create political opportunities for policy change.

In 74 cases out of a total of 151 reported mass shootings in the United States since 1982, the shooter(s) displayed prior signs of mental health problems. In 17 cases out of 150, there were no signs of mental health issues in the shooters.

As of September 2024, California had the most mass shootings in the United States, with 26 total shootings since 1982. The source defines a mass shooting as a shooting where three or more people were killed. Recently, a mass shooting occurred in the state of Maine on October 26, 2023, during which one of the highest number of fatalities from a mass shooting was recorded after Robert Card opened fire in a bowling alley and a bar, killing 18 and injuring 13 others. Firearms in the U.S. Mass shootings in the United States are disturbingly common. In comparison with other Western countries, there are significantly more shootings in the U.S., which some theorize is due to the relatively lax gun control laws. Gun control laws in the U.S. are dependent on the state, and the right to own a firearm is enshrined in the United States Constitution. Mass shootings The worst mass shooting in the U.S. was the Las Vegas Strip massacre in 2017, which resulted in 58 deaths and 546 injuries. 13 of the worst mass shootings in the United States have occurred since 2015 and the vast majority of these incidents in the U.S. have been carried out by shooters who are White and male.

How do events that highlight a policy issue impact political preferences? In this paper, I analyze the impact of mass shootings on voter behavior. I show that, conditional on population, mass shootings are largely random events. Using a difference-in-differences strategy, I find that mass shootings result in a 1.7 percentage point loss in Republican vote share in counties where they occur. Identification that relies on comparing successful and failed mass shootings yields similar results. Mass shootings lead to an increase in the salience of gun policy and increase the divide on gun policy among both voters and politicians. Democrats (Republicans) tend to demand even stricter (looser) gun control after mass shootings. These results suggest that increasing the salience of an issue may polarize the electorate.

Between 1970 and June 16, 2020, 175 school shootings were perpetrated by 17-year-olds. 16-year-olds perpetrated the second highest number of school shootings, with 163 shootings.

From 1966 to 2021, there has been a variety of different motives behind mass shootings in the United States. Symptoms of psychosis, regardless of the extent, were the most likely motive of mass shooters, accounting for 30.2 percent, followed by employment, interpersonal conflict, domestic spillage, and relationship issues.

On October 1, 2017, the highest number of fatalities from a mass shooting in the United States was recorded when Stephen Paddock attacked a crowd of concert-goers on the Las Vegas strip, killing 58 and injuring 546 others, then taking his own life before authorities could apprehend him. Most recently, one of the worst mass shootings in the U.S. occurred in Maine on October 26, 2023, when Robert Card, an Army reservist and firearms instructor, opened fire in a bowling alley and a bar, killing 18 and injuring 13 others. Card then became the focus of a two-day-long manhunt, until he was found dead from a self-inflicted gunshot.

100 of the mass shootings in the United States between 1982 and September 2024 involved weapons which were obtained legally; a clear majority. Only 16 incidents involved guns that were obtained illegally. Legally owned firearms in the U.S. Within the United States, one must be at least 18 years old in order to purchase shotguns, rifles, and ammunition, and at least 21 years old to purchase all other firearms. Some people may be restricted from owning firearms, such as individuals who have been dishonorably discharged from the military or tourists. Guns must be sold through licensed dealers, and purchasers must undergo a background check. However, the much-discussed “gun show loophole” allows people to purchase firearms from a flea market, gun show, online, or from a personal collector without a background check. The national firearm conversation The right to own a gun in the United States is protected by the 2nd Amendment of the Constitution. While changing a part of the Bill of Rights (the first 10 amendments to the Constitution) would be extremely difficult, the issue of gun rights has become a highly controversial, and highly partisan, topic in the national conversation. For example, a majority of Republicans believe that if legal gun ownership is controlled, that there will not be a difference in the number of mass shootings. In contrast, most Democrats believe the number will decrease.

Number and percentage of homicide victims, by type of firearm used to commit the homicide (total firearms; handgun; rifle or shotgun; fully automatic firearm; sawed-off rifle or shotgun; firearm-like weapons; other firearms, type unknown), Canada, 1974 to 2018.

Handguns are the most common weapon type used in mass shootings in the United States, with a total of 167 different handguns being used in 117 incidents between 1982 and September 2024. These figures are calculated from a total of 151 reported cases over this period, meaning handguns are involved in about 78 percent of mass shootings. The involvement of semi-automatic rifles in mass shootings Owing to their use in several high-profile mass shootings, there has been much public discussion over the suitability or necessity of assault weapons for the purpose of self-defense. While any definition of assault weapon is contentious, semi-automatic rifles are generally the main focus of debates around this issue. Since 1982, there has been a known total 65 mass shootings involving rifles, mostly semi-automatics. This figure is underreported, however, as it excludes the multiple semi-automatic (and fully automatic) rifles used in the 2017 Las Vegas Strip massacre – the worst mass shooting in U.S. history, killing 58 and wounding 546. In fact, semi-automatic rifles were featured in four of the five deadliest mass shootings, being used in the Orlando nightclub massacre, Sandy Hook Elementary massacre and Texas First Baptist Church massacre. Mass shootings and gun control Despite evidence of strict gun control measures reducing the frequency and severity of mass shootings in countries like Australia, citizens in the United States remain deeply divided over the issue. According to a survey about the expected impact of gun laws on the number of mass shootings, a slim majority of Americans believe that gun control measures will have little-to-no effect. Most likely, this opinion is influenced by an underlying commitment among many in the U.S. to the greater importance of protecting gun ownership rights than limiting access to firearms. This sits in sharp contrast to many other developed countries. For example, most Canadians support a ban on civilian owned firearms.

The global bulletproof backpack market is experiencing robust growth, driven by increasing concerns over mass shootings and active shooter events in schools and public spaces. This demand is particularly strong in North America and Europe, regions with established safety consciousness and higher disposable incomes. While precise market size figures for 2025 are unavailable, a logical estimation based on industry reports and the stated CAGR would place the market value at approximately $150 million. This figure reflects a steady increase from previous years, fueled by technological advancements leading to lighter, more comfortable, and discreet bulletproof backpack designs. The market segmentation reveals a significant portion of sales concentrated in the $200-$500 price range, catering to a balance of affordability and desired protection levels. The student segment is a crucial driver, while police and military segments represent niche applications for specialized products. Growth is further fueled by rising awareness of personal safety and the adoption of protective measures by both civilians and professionals. However, restraints include high initial costs for consumers, concerns over the potential stigmatization of carrying these backpacks, and the need for continuous advancements in material science and design to further improve comfort and discretion. Looking forward, the market's expansion is projected to continue throughout the forecast period (2025-2033). A conservative CAGR estimate, assuming steady but not explosive growth given the inherent market limitations, would suggest a gradual increase to approximately $300 million by 2033. This growth will be influenced by factors such as evolving product designs offering better protection and comfort, expansion into emerging markets with rising disposable incomes, and continued marketing campaigns highlighting the benefits of bulletproof backpacks. Continued innovation in materials and manufacturing techniques will likely drive prices down over time, making these essential safety items more accessible to a broader demographic. Companies in the market are focusing on improving product features, expanding distribution networks, and strengthening brand recognition to maintain a competitive edge.

Introduction: Following mass traumatic events, greater exposure to traditional media like television (TV) about the event is associated with higher burden of post-traumatic stress disorder (PTSD). However, we know little about how social media exposure, combined with other media sources, shapes the population burden of PTSD following mass traumatic events.Materials and Methods: We built a microsimulation of 1,18,000 agents that was demographically comparable to the population of Parkland and Coral Springs, Florida that experienced the Stoneman Douglas High School shooting in 2018. We parametrized the model using data from prior traumatic events and built an internal social network structure to facilitate the estimation of community PTSD prevalence following exposure to TV and social media coverage of the shooting.Results: Overall, PTSD prevalence in the community due to exposure to TV coverage of the shooting was 3.1%. Shifting the whole population's hours of TV watching to the lower half of the population distribution decreased PTSD prevalence to 1.3% while increasing TV watching to the upper half of the distribution increased the prevalence to 3.5%. Casual (i.e., viewing posts) social media use in addition to exposure to TV coverage increased PTSD prevalence to 3.4%; overall prevalence increased to 5.3% when agents shared videos related to the shooting on social media.Conclusion: This microsimulation shows that availability and exposure to media coverage of mass traumatic events, particularly as social media becomes more ubiquitous, has the potential to increase community PTSD prevalence following these events. Future research could fruitfully examine the mechanisms that might explain these associations and potential interventions that can mitigate the role of media in shaping the mental health of populations following traumatic events.

The global gunfire locator market for homeland security applications is experiencing robust growth, driven by escalating concerns over public safety and the need for advanced threat detection systems. This market, estimated at $500 million in 2025, is projected to exhibit a Compound Annual Growth Rate (CAGR) of 12% from 2025 to 2033. This significant expansion is fueled by several key factors. Firstly, increasing urbanization and population density create a higher risk of mass shootings and other firearm-related incidents, necessitating effective and rapid response mechanisms. Secondly, technological advancements in acoustic and optical sensor technologies, along with improved data analytics capabilities, are enhancing the accuracy, range, and real-time capabilities of gunfire locators. Furthermore, government initiatives and increased budgetary allocations towards homeland security infrastructure are contributing to market expansion. The growing adoption of integrated security systems that combine gunfire locators with other surveillance technologies is further boosting market growth. Market segmentation reveals strong demand across various applications, including fixed/ground installations in high-risk locations such as schools and government buildings, vehicle-mounted systems for mobile patrol units, and soldier-borne systems for enhanced situational awareness. The acoustic technology segment currently dominates, but optical technologies are rapidly gaining traction due to their superior accuracy and ability to discriminate between different sound sources, reducing false alarms. Key players in this market, including Raytheon, Thales, and others, are focused on developing innovative products and expanding their market presence through strategic partnerships and acquisitions. While factors such as the high initial investment costs associated with these systems and potential regulatory hurdles can pose restraints, the overall market outlook remains highly positive, projected to reach approximately $1.5 billion by 2033, driven by the ever-increasing need for advanced homeland security solutions. This report provides a detailed analysis of the global Gunfire Locator For Homeland market, projected to reach a valuation exceeding $2 billion by 2030. It delves into market dynamics, competitive landscapes, technological advancements, and future growth projections, providing invaluable insights for stakeholders across the defense, homeland security, and law enforcement sectors. This report utilizes rigorous market research methodologies and leverages data from leading industry players such as Raytheon, Thales, and others to deliver actionable intelligence.