As of August 2025, 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.

From 2008 to April 25, 2025, the District of Columbia had the highest rate of school shootings nationwide, totaling around **** school shootings per 100,000 residents. Louisiana, Delaware, Maryland, and Alabama rounded out the top five states with the highest school shooting rates relative to their populations. In contrast, there were no school shootings recorded in Montana, Wyoming, New Hampshire, Vermont, and Rhode Island within the provided time period. In addition to K-12 schools and college campuses, gun-related violence in the United States often occurs at workplaces, places of worship, and restaurants and bars. The source defines school shootings as incidents of gun violence which occurred on school property, from kindergartens through colleges/universities, and at least one person was shot, not including the shooter. School property includes, but is not limited to, buildings, fields, parking lots, stadiums and buses. Accidental discharges of firearms are included, as long as at least one person is shot, but not if the sole shooter is law enforcement or school security.

THIS DATASET WAS LAST UPDATED AT 8:11 AM EASTERN ON SEPT. 22

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.

As of July 14, 2025, there have been a total of 277 school shootings in California since 1966, the most out of any state. Texas had the second highest number of school shootings within this time period, with 237 shootings. The source defines a school shooting as every time a gun is brandished, fired, or a bullet hits school property for any reason, regardless of the number of victims (including zero), time, day or the week, or reason, including gang shootings, domestic violence, shootings at sports games and after hours school events, suicides, fights that escalate into shootings, and accidents.

Data on GDP Per capita of countries and their Human Development Index Ranking. The data is from the 2007/2008 United Nations Human Development Report.

This dataset lists the number of well known school shootings by state. Some states have had more incidents than others. School shooting is a term popularized in American and Canadian media to describe gun violence at educational institutions, especially the mass murder or spree killing of people connected with an institution. A school shooting can be perpetrated by one or more students, expelled students, alumni, faculty members, or outsiders. Unlike acts of revenge against specific people, school shootings usually involve multiple intended or actual victims, often randomly targeted. Source: Wikipedia section on school shootings http://en.wikipedia.org/wiki/School_shootings#List_of_school_shootings

This dataset shows the count of substructures per county in the United States. the count is divided into safety ratings for each county, with values from 0-9. '0' Failed '1' Imminent '2' Critical '3' Serious '4' Poor '5' Fair '6' Satisfactory '7' Good '8' Very good '9' Excellent 'Unk' Unknown 'N' Not applicable Also Dangerous is summation of 0,1,2 and 3. Risky is summation of 4, 5 and 6. Safe is summation of 7, 8 and 9. Data Source: http://www.fhwa.dot.gov/bridge/britab.htm

This is the World Freedom index, By the State of World Liberty Project. It ranks various countries by various forms of freedom and created an index to see which countries had the most freedom. USA finished 8th, with Estonia in 1st place and North Korea having the least freedom. Source URL: http://www.stateofworldliberty.org/report/rankings.html This Dataset has a ranking for the countries, just to be clear, when you map out the rankings of countries, the highest ranked countries will not be the brightest on the map. Estonia is Ranked #1, but the value of 1 is lower than the value assigned to North Korea (158). so just be aware of that. In short, for mapping, use the Scores not the Ranks.

In recent years, gun violence in the United States has become an alarmingly common occurrence. From 2016, there has been over ****** homicides by firearm in the U.S. each year and firearms have been found to make up the majority of murder weapons in the country by far, demonstrating increasing rates of gun violence occurring throughout the nation. As of 2025, Mississippi was the state with the highest gun violence rate per 100,000 residents in the United States, at **** percent, followed by Louisiana, at **** percent. In comparison, Massachusetts had a gun violence rate of *** percent, the lowest out of all the states. The importance of gun laws Gun laws in the United States vary from state to state, which has been found to affect the differing rates of gun violence throughout the country. Fewer people die by gun violence in states where gun safety laws have been passed, while gun violence rates remain high in states where gun usage is easily permitted and even encouraged. In addition, some states suffer from high rates of gun violence despite having strong gun safety laws due to gun trafficking, as traffickers can distribute firearms illegally past state lines. The right to bear arms Despite evidence from other countries demonstrating that strict gun control measures reduce rates of gun violence, the United States has remained reluctant to enact gun control laws. This can largely be attributed to the Second Amendment of the Constitution, which states that citizens have the right to bear arms. Consequently, gun control has become a highly partisan issue in the U.S., with ** percent of Democrats believing that it was more important to limit gun ownership while ** percent of Republicans felt that it was more important to protect the right of Americans to own guns.

This dataset illustrates the largest difference between high and low temperatures and the smallest difference between high and low temperatures in cities with 50,000 people or more. A value of -1 means that the data was not applicable. Also included are the rankings, the inverse ranking to be used for mapping purposes, the popualtion, the name of city and state, and the temperature degree difference. Source City-Data URL http//www.city-data.com/top2/c489.html http//www.city-data.com/top2/c490.html Date Accessed November 13,2007

This data reports Internet crime perpetrators per capita (per 100,000 people) by State for 2007. The data was extracted from the 2007 Internet Crime Report prepared by The National White Collar Crime Center, the Bureau of Justice Assistance, FBI. Further details provided in the link to the report in the URL below.

The United States recorded *** school shootings between 2009 and 2018 - 57 times as many as occurred in the six other Group of Seven (G7) countries combined. The G7 countries with the next-highest number of school shootings were Canada and France, with two apiece.

The U.S. Census released the data on annual change in minority population by state on 1st May, 2008. here is the press-release: http://www.census.gov/Press-Release/www/releases/archives/population/011910.html

Turks and Caicos Islands saw a murder rate of ***** per 100,000 inhabitants, making it the most dangerous country for this kind of crime worldwide as of 2024. Interestingly, El Salvador, which long had the highest global homicide rates, has dropped out of the top 29 after a high number of gang members have been incarcerated. Meanwhile, Colima in Mexico was the most dangerous city for murders. Violent conflicts worldwide Notably, these figures do not include deaths that resulted from war or a violent conflict. While there is a persistent number of conflicts worldwide, resulting casualties are not considered murders. Partially due to this reason, homicide rates in Latin America are higher than those in Afghanistan or Syria. A different definition of murder in these circumstances could change the rate significantly in some countries. Causes of death Also, noteworthy is that murders are usually not random events. In the United States, the circumstances of murders are most commonly arguments, followed by narcotics incidents and robberies. Additionally, murders are not a leading cause of death. Heart diseases, strokes and cancer pose a greater threat to life than violent crime.

Overall Rank for each state was obtained in the following manner. First, we converted the 2005 (or 2004, depending on the indicator) state numerical values for each of the 10 key indicators into standard scores. We then summed those standard scores to create a total standard score for each of the 50 states. Finally, we ranked the states on the basis of their total standard score in sequential order from highest/best (1) to lowest/ worst (50). Standard scores were derived by subtracting the mean score from the observed score and dividing the amount by the standard deviation for that distribution of scores. All measures were given the same weight in calculating the total standard score.

This data reports Internet crime complainents per capita (per 100,000 people) by State for 2007. The data was extracted from the 2007 Internet Crime Report prepared by The National White Collar Crime Center, the Bureau of Justice Assistance, FBI. Further details provided in the link to the report in the URL below.

The shape file shows TV ratings by Lower 48 Designated Market Areas (DMA) , also known as TV markets for 2007-2008. It also has estimates of number of household Television sets as well as the percent of TV viewership by DMA. Also known as Nielsen Ratings, the data is used heavily for advertising and marketing sectors.

This dataset shows where media and press are most free to express their views and opinions. Countries rankings are based on laws, violence, and deaths of reporters and journalists. This is a Different measure of freedom than the world freedom index but just as important. This dataset shows the availability of dissenting views and opinions allowed within a Country. Source URL: http://www.rsf.org/article.php3?id_article=11715

This data set illustrates the rankings of the best places to work within the Federal Government for 2007. Data for 2005 and the percent change between the given years is also present. http://bestplacestowork.org/BPTW/rankings/index.php?t=scores_large&c=index August 31, 2007

This dataset has ratings for superstructures by county. each county counts the number of each superstructures with a particular rating. values range from 0-9. '0' Failed '1' Imminent '2' Critical '3' Serious '4' Poor '5' Fair '6' Satisfactory '7' Good '8' Very good '9' Excellent 'Unk' Unknown 'N' Not applicable Also Dangerous is summation of 0,1,2 and 3. Risky is summation of 4, 5 and 6. Safe is summation of 7, 8 and 9. Data source: http://www.fhwa.dot.gov/bridge/britab.htm