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.

Between 1982 and August 2025, 84 out of the 155 mass shootings in the United States were carried out by white shooters. By comparison, the perpetrator was Black 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.

THIS DATASET WAS LAST UPDATED AT 8:11 PM EASTERN ON AUG. 30

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.

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.

The second-deadliest workplace shooting in the United States took place in Edmond, Oklahoma in 1986 at a United States post office. There were 15 fatalities and six injuries in this shooting, and the incident inspired the American phrase “going postal.”

Workplace shootings

A mass shooting in the United States is generally defined as an incident where four or more people were injured or killed, though this can vary by source. It is sometimes difficult to identify the cause of workplace killings (also called rampage killings), although many involved disgruntled workers and some involve perpetrators with mental health problems.

Mass shootings in the United States

The vast majority of mass shootings in the United States are perpetrated by male assailants, and only four shootings have been carried out by women since 1982. Additionally, most of the weapons used in mass shootings were acquired through legal means, with only 16 incidents involving illegally obtained weapons since 1982.

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.

From 2000 to 2022, the majority of active shooters in education settings in the United States were male, with ** active shooters in elementary and secondary schools and ** active shooters at postsecondary institutions identifying as male. In comparison, only *** active shooters at both elementary and secondary schools and at postsecondary institutions in the United States identified as female within the provided time period. According to the Federal Bureau of Investigation (FBI), an active shooter is defined as "one or more individuals actively engaged in killing or attempting to kill people in a populated area."

The data set contains 2,528 coded articles from three relevant news outlets in Mexico.

The newspapers in the study were chosen for their audience scope, considering they inform on general topics, and have national coverage in print and digital versions, the latter available for consultation since 2014. The newspapers that have different versions per region were discarded. Five newspapers have these characteristics in Mexico. To ensure equal representation in ideologies we selected one left-leaning, one right-leaning, and one centre-leaning example. We prioritized the ones with the most visits to their websites, as data was collected through their digital versions: (1) El Universal, first place in number of visits, centre ideology and open access to its online library; (2) Excélsior, second place in visits, left-wing ideology and open access to its online library; and (3) Reforma, third place in visits, right-wing ideology and online library available by paid subscription.

The articles were collected using the search engine on each outlet’s website covering a period of seven semesters: from July 2014 (the date of the first government council meeting to study the possibility of declaring an ‘alert for gender violence’ due to the high rates of femicides) to December 2017 (date on which this research registered the increase of media attention stabilizes). Two filtering processes were used: entering keywords: 1) ‘femicide’ (feminicidio), from the results all articles that had the keyword in the headline, dealt with the topic in the body of the article, or reported on specific cases were added to the database. We discarded those that had the word in the body of the article, but the topic was not related. 2) ‘Dead woman’ (mujer muerta), the intention is to include femicides even if the news outlet did not describe them as such. Articles reporting women murdered by (ex)partners, family, or acquaintances, and single or mass murders of women possibly committed by organized crime groups were added to the database. Those referring to accidental deaths and that explicitly stated that the causes of death were not related to gender violence were discarded. The process produced a unit of analysis of N=2,528 articles from the three outlets. El Universal 1031, Reforma 969, and Excélsior 528.

In response to a Public Records Act (PRA) request submitted by the Association for the Advancement of Civil Liberties (AACL) about the month of May having been designated as “Mental Health Awareness Month,” the San Francisco Arts Commission (SFAC) denied having held conversations about [1] Amber Heard as a Caucasian woman, who had turned 30 (thirty) years of age on April 22nd 2016; [2] Amber Heard as a woman, who had attended the 2016 Coachella Valley Music and Arts Festival on her 30th birthday; [3] the April 27th 2022 highly publicized accusations made against Amber Heard alleging that she had defecated in the matrimonial bed she shared with her ex-husband on the occasion of her 30th birthday; [4] the racist mental diagnosis known as “drapetomania,” which has now been totally discredited; [5] the mental illness of “schizophrenia” having historically been associated with white women prior to 1960; [6] the reasons why Black/African American people have increasingly been diagnosed with “schizophrenia” after 1960; [7] the reasons why Black/African American people are five to seven times more likely to be diagnosed with “schizophrenia” compared to white people.

As a matter of principle, the AACL unequivocally denounces violence committed against women irrespective of their racial backgrounds, their sexual orientations, their national origins, their religious affiliations and/or their disability status. In the judgment of the AACL, Amber Heard was subject of intense online vitriol hatred, which ultimately impacted the outcome of her defamation trial in a very adverse manner (this Calendar Year 2022). The AACL deeply regrets the decision of the judicial branch of the U.S government (the courts) [1] to issue rulings that were not favorable to Amber Heard and [2] to reject the arguments presented in her appeal (which were both convincing and persuasive). Be well. Take care. Keep yourselves at arms distance.

Michael Ayele (a.k.a) W Anti-Racist Human Rights Activist Audio-Visual Media Analyst Anti-Propaganda Journalist