THIS DATASET WAS LAST UPDATED AT 8:11 AM EASTERN ON SEPT. 17

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.

The data on mass shootings is from https://www.gunviolencearchive.org/ . This dataset on mass shootings for the period 2014-2023 was provided on Feb 19, 2024 by the Data Manager (Ms. Sharon Williams) at the Gun Violence Archive (https://www.gunviolencearchive.org/) on a data request. Minimal curation was done on this data – the date variable was split into year, month and day. See the codebook for full details.A mass shooting is defined as four or more people injured or killed, because of firearms, excluding the shooter.The curated datasets are included here along with a research question and guiding questions.For information of how this data is collected, go to: https://www.gunviolencearchive.org/explainerDefinition for mass shooting and mass murder from the above website is given verbatim below:Mass Shooting Methodology and Reasoning: Mass Shootings are, for the most part an American phenomenon. While they are generally grouped together as one type of incident they are several different types including public shootings, bar/club incidents, family annihilations, drive-by, workplace and those which defy description but with the established foundation definition being that they have 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. GVA also presents the count of Mass Murder which, like the FBI's definition is four or more victims, killed, not including the shooter. Mass Murder by gun is a subset of the Mass Shooting count.

This dataset displays all the hazardous waste sites in the United States and it's Territories as of 5.08. The data comes from the Agency for Toxic Substances and Disease Registry(ATSDR). The dataset contains information about the site: Site ID Site Name CERCLIS # Address City State County Latitude Longitude Population Region # Congressional Districts Federal Facility National Priorities List Status Ownership Status Classification For more information go to the Agency for Toxic Substances and Disease Registry(ATSDR)website at http://www.atsdr.cdc.gov

This dataset was found online at the Association of Religious Data Archives (ARDA) website. http://www.thearda.com/ . This data set shows information on religous groups throughout the United States. All data was uploaded as a polypoint centroids per county in the United States, in shapefile format. This Data set shows the Total congregations, Total Adherents, and Rate of Adherence per 1000 population for All religions in the United States and for the Mainline Religions.

This dataset includes births, deaths and the ratio of births to deaths by metropolitan area for the years 2000-2006. The actual births and deaths for 2000 and estimates were taken from the U.S. Census Components of Population Change. Ratios were calculated based on that data.

This dataset was retrieved from the U.S. Department of Justice Federal Bureau of Investigation Criminal Justice Information Services Division website on February 29, 2008. "This table provides the estimated number of offenses and the actual number of offenses reported in the Metropolitan Statistical Areas (MSA), cities outside metropolitan areas, and nonmetropolitan counties, and the rate (per 100,000 inhabitants) for each grouping, and the estimated population for each state" however to simplify the dataset, I only included the state total and the rate for each state. Data for Puerto Rico was not included. "The FBI collects these data through the Uniform Crime Reporting (UCR) Program". Please see the Data Declaration for further information on the data set. Values of -1 represent no value.

All the data for this dataset is provided from CARMA: Data from CARMA (www.carma.org) This dataset provides information about Power Plant emissions in the USA. Power Plant emissions from all power plants in the United Staes were obtained by CARMA for the past (2000 Annual Report), the present (2007 data), and the future. CARMA determine data presented for the future to reflect planned plant construction, expansion, and retirement. The dataset provides the name, company, parent company, city, state, zip, county, metro area, lat/lon, and plant id for each individual power plant. The dataset reports for the three time periods: Intensity: Pounds of CO2 emitted per megawatt-hour of electricity produced. Energy: Annual megawatt-hours of electricity produced. Carbon: Annual carbon dioxide (CO2) emissions. The units are short or U.S. tons. Multiply by 0.907 to get metric tons. Carbon Monitoring for Action (CARMA) is a massive database containing information on the carbon emissions of over 50,000 power plants and 4,000 power companies worldwide. Power generation accounts for 40% of all carbon emissions in the United States and about one-quarter of global emissions. CARMA is the first global inventory of a major, sector of the economy. The objective of CARMA.org is to equip individuals with the information they need to forge a cleaner, low-carbon future. By providing complete information for both clean and dirty power producers, CARMA hopes to influence the opinions and decisions of consumers, investors, shareholders, managers, workers, activists, and policymakers. CARMA builds on experience with public information disclosure techniques that have proven successful in reducing traditional pollutants. Please see carma.org for more information http://carma.org/region/detail/202

This dataset was created from the CDC's National Vital Statistics Reports Volume 56, Number 6. The dataset includes all data available from this report by state level and includes births by race and Hispanic origin, births to unmarried women, rates of cesarean delivery, and twin and multiple birth rates. The data are final for 2005. No value is represented by a -1. "Descriptive tabulations of data reported on the birth certificates of the 4.1 million births that occurred in 2005 are presented. Denominators for population-based rates are postcensal estimates derived from the U.S. 2000 census".

This is the monthly data for U.S. employment and unemployment by state including some numbers for Puerto Rico. This dataset was accessed on April 7th 2008. The data for February 2008 are preliminary. The data presented are seasonally adjusted although the unadjusted numbers are also available. Unavailable data are represented as -1. The dataset is taken from Tables 3 and 5 from the United States Department of Labor, Bureau of Labor Statistics. It includes the civilian labor force, the unemployed in numbers and percentages, and employment by industry. Data from table 3 "refer to place of residence. Data for Puerto Rico are derived from a monthly household survey similar to the Current Population Survey. Area definitions are based on Office of Management and Budget Bulletin No. 08-01, dated November 20, 2007, and are available at http://www.bls.gov/lau/lausmsa.htm. Estimates for the latest month are subject to revision the following month". Data from table 5 "are counts of jobs by place of work. Estimates are currently projected from 2007 benchmark levels. Estimates subsequent to the current benchmarks are provisional and will be revised when new information becomes available. Data reflect the conversion to the 2007 version of the North American Industry Classification System (NAICS) as the basis for the assignment and tabulation of economic data by industry, replacing NAICS 2002. For more details, see http://www.bls.gov/sae/saenaics07.htm.

The United States Military Installations database contains the boundaries and location information for important military installations in the United States and Puerto Rico. The database includes records for 405 military installations. Source: National Transportation Atlas Database URL: http://www.bts.gov/publications/national_transportation_atlas_database/2006/

This dataset displays the Blood Alcohol Concentration (BAC) of the driver for all fatal traffic accidents in 2006. The data is divided on a state level, and was collected from the Fatality Analysis Reporting System at: http://www-fars.nhtsa.dot.gov/States/StatesAlcohol.aspx Access Date: November 16, 2007

This dataset displays the inmate populations for all the Federal Prisons throughout the United States on 7.2.08. This weekly Population Report can be found on the Bureau of Prisons website at bop.gov. These facilities are positioned by their lat/lon and this dataset is updated on a weekly basis.

This dataset has been migrated from our Geocommons platform, and lacks a description from the original posting user. This is not a Fortiusone provided dataset. Please keep this in mind, and make of the dataset what you will. Thank you for visiting Finder!

This dataset displays the Real GDP by metropolitan area for the years 2001-2005. For each of the posted metropolitan areas Millions of chained dollars and the percentage change from the previous year is posted. This data was geocoded according to city and state locations. During the geocoding process 233/363 records from the original dataset were successfully geocoded. The reason for this is that during the process is that the dataset often groups cities together into one metropolitan area, which were unable to be properly coded. This data was collected from the Bureau of Economic analysis at their web page at: http://www.bea.gov/newsreleases/regional/gdp_metro/gdp_metro_newsrelease.htm Access Date: October 29, 2007

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 dataset was retrieved from the U.S. Department of Justice Federal Bureau of Investigation Criminal Justice Information Services Division website on February 29, 2008. "This table provides arrest data for 29 separate UCR offenses for each state for 2006". The table provides data for total arrests by class of crime. "The FBI collects these data through the Uniform Crime Reporting (UCR) Program". Estimated population was added for each state for 2006 that appeared on Table 5 of the data from 2006. Please see the Data Declaration for further information on the data set. Values of -1 represent no value.

All the data for this dataset is provided from CARMA: Data from CARMA (www.carma.org) This dataset provides information about Power Plant emissions in Chile. Power Plant emissions from all power plants in Chile were obtained by CARMA for the past (2000 Annual Report), the present (2007 data), and the future. CARMA determine data presented for the future to reflect planned plant construction, expansion, and retirement. The dataset provides the name, company, parent company, city, state, zip, county, metro area, lat/lon, and plant id for each individual power plant. The dataset reports for the three time periods: Intensity: Pounds of CO2 emitted per megawatt-hour of electricity produced. Energy: Annual megawatt-hours of electricity produced. Carbon: Annual carbon dioxide (CO2) emissions. The units are short or U.S. tons. Multiply by 0.907 to get metric tons. Carbon Monitoring for Action (CARMA) is a massive database containing information on the carbon emissions of over 50,000 power plants and 4,000 power companies worldwide. Power generation accounts for 40% of all carbon emissions in the United States and about one-quarter of global emissions. CARMA is the first global inventory of a major, sector of the economy. The objective of CARMA.org is to equip individuals with the information they need to forge a cleaner, low-carbon future. By providing complete information for both clean and dirty power producers, CARMA hopes to influence the opinions and decisions of consumers, investors, shareholders, managers, workers, activists, and policymakers. CARMA builds on experience with public information disclosure techniques that have proven successful in reducing traditional pollutants. Please see carma.org for more information

This dataset gives the average annual number of deaths during a year per 1,000 population at midyear; also known as crude death rate. This information was found at the CIA's World Factbook 2007. The site had this to say about death rate, "The death rate, while only a rough indicator of the mortality situation in a country, accurately indicates the current mortality impact on population growth. This indicator is significantly affected by age distribution, and most countries will eventually show a rise in the overall death rate, in spite of continued decline in mortality at all ages, as declining fertility results in an aging population." Source: https://www.cia.gov/library/publications/the-world-factbook/docs/notesanddefs.html#2010 Accessed: 9.17.07

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 explores radio station information in the AM broadcast band (530 kHz to 1700 kHz).