THIS DATASET WAS LAST UPDATED AT 2:10 AM EASTERN ON OCT. 7

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.

Dataset

This dataset was created by Denis Afonin

Released under CC0: Public Domain

Contents

Dataset

This dataset was created by JD Torres

Contents

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.

BackgroundGun violence has shortened the average life expectancy of Americans, and better knowledge about the root causes of gun violence is crucial to its prevention. While some empirical evidence exists regarding the impacts of social and economic factors on violence and firearm homicide rates, to the author’s knowledge, there has yet to be a comprehensive and comparative lagged, multilevel investigation of major social determinants of health in relation to firearm homicides and mass shootings.Methods and findingsThis study used negative binomial regression models and geolocated gun homicide incident data from January 1, 2015, to December 31, 2015, to explore and compare the independent associations of key state-, county-, and neighborhood-level social determinants of health—social mobility, social capital, income inequality, racial and economic segregation, and social spending—with neighborhood firearm-related homicides and mass shootings in the United States, accounting for relevant state firearm laws and a variety of state, county, and neighborhood (census tract [CT]) characteristics. Latitude and longitude coordinates on firearm-related deaths were previously collected by the Gun Violence Archive, and then linked by the British newspaper The Guardian to CTs according to 2010 Census geographies. The study population consisted of all 74,134 CTs as defined for the 2010 Census in the 48 states of the contiguous US. The final sample spanned 70,579 CTs, containing an estimated 314,247,908 individuals, or 98% of the total US population in 2015. The analyses were based on 13,060 firearm-related deaths in 2015, with 11,244 non-mass shootings taking place in 8,673 CTs and 141 mass shootings occurring in 138 CTs. For area-level social determinants, lag periods of 3 to 17 years were examined based on existing theory, empirical evidence, and data availability. County-level institutional social capital (levels of trust in institutions), social mobility, income inequality, and public welfare spending exhibited robust relationships with CT-level gun homicide rates and the total numbers of combined non-mass and mass shooting homicide incidents and non-mass shooting homicide incidents alone. A 1–standard deviation (SD) increase in institutional social capital was linked to a 19% reduction in the homicide rate (incidence rate ratio [IRR] = 0.81, 95% CI 0.73–0.91, p < 0.001) and a 17% decrease in the number of firearm homicide incidents (IRR = 0.83, 95% CI 0.73–0.95, p = 0.01). Upward social mobility was related to a 25% reduction in the gun homicide rate (IRR = 0.75, 95% CI 0.66–0.86, p < 0.001) and a 24% decrease in the number of homicide incidents (IRR = 0.76, 95% CI 0.67–0.87, p < 0.001). Meanwhile, 1-SD increases in the neighborhood percentages of residents in poverty and males living alone were associated with 26%–27% and 12% higher homicide rates, respectively. Study limitations include possible residual confounding by factors at the individual/household level, and lack of disaggregation of gun homicide data by gender and race/ethnicity.ConclusionsThis study finds that the rich–poor gap, level of citizens’ trust in institutions, economic opportunity, and public welfare spending are all related to firearm homicide rates in the US. Further establishing the causal nature of these associations and modifying these social determinants may help to address the growing gun violence epidemic and reverse recent life expectancy declines among Americans.

As of June 19, 116 school shooting incidents were recorded in K-12 schools in the United States in 2025. Within the provided time period, the greatest number of K-12 school shootings was recorded in 2023, at 350. 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.

Source: https://www.gunviolencearchive.org/reports/mass-shooting

Compiled with month and year added to each record. Wanted to understand how often these occur.

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 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.

The United States MSA Boundaries data set contains the boundaries for metropolitan statistical areas in the United States. The data set contains information on location, identification, and size. The database includes metropolitan boundaries within all 50 states, the District of Columbia, and Puerto Rico. The general concept of a metropolitan area (MA) is one of a large population nucleus, together with adjacent communities that have a high degree of economic and social integration with that nucleus. Some MAs are defined around two or more nuclei. Each MA must contain either a place with a minimum population of 50,000 or a U.S. Census Bureau-defined urbanized area and a total MA population of at least 100,000 (75,000 in New England). An MA contains one or more central counties. An MA also may include one or more outlying counties that have close economic and social relationships with the central county. An outlying county must have a specified level of commuting to the central counties and also must meet certain standards regarding metropolitan character, such as population density, urban population, and population growth. In New England, MAs consist of groupings of cities and towns rather than whole counties. The territory, population, and housing units in MAs are referred to as "metropolitan." The metropolitan category is subdivided into "inside central city" and "outside central city." The territory, population, and housing units located outside territory designated "metropolitan" are referred to as "non-metropolitan." The metropolitan and non-metropolitan classification cuts across the other hierarchies; for example, generally there are both urban and rural territory within both metropolitan and non-metropolitan areas.

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 Tally's up the number of Olympic Gold medal winners per state. if an athlete has earned multiple medals, they only count as one. Its just the way it works out. anyways, this was pulled from Wikipedia.org, and is incomplete, these aren't total counts, these are just counts that i could find data for. If you'd like to try to do better, feel free. Source URL: http://en.wikipedia.org/wiki/Category:Olympic_gold_medalists_for_the_United_States

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.

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 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.

A joint venture involving the National Atlas programs in Canada (Natural Resources Canada), Mexico (Instituto Nacional de Estadstica Geografa e Informtica), and the United States (U.S. Geological Survey), as well as the North American Commission for Environmental Co-operation, has led to the release (June 2004) of several new products: an updated paper map of North America, and its associated geospatial data sets and their metadata. These data sets are available online from each of the partner countries both for visualization and download. The North American Atlas data are standardized geospatial data sets at 1:10,000,000 scale. A variety of basic data layers (e.g. roads, railroads, populated places, political boundaries, hydrography, bathymetry, sea ice and glaciers) have been integrated so that their relative positions are correct. This collection of data sets forms a base with which other North American thematic data may be integrated. Any data outside of Canada, Mexico, and the United States of America included in the North American Atlas data sets is strictly to complete the context of the data. The North American Atlas - Railroads data set shows the railroads of North America at 1:10,000,000 scale. The railroads selected for this data set are either rail links between major centres of population or major resource railways. There is no classification of rail lines. This data set was produced using digital files supplied by Natural Resources Canada, Instituto Nacional de Estadstica Geografa e Informtica, and the U.S. Geological Survey.

This dataset shows the number of people that are in prison by state in 2006 and 2007. These numbers are then compared to show the difference between the two years and a percentage of change is given as well. This data was brought to our attention by the Pew Charitable Trusts in their report titled, One in 100: Behind Bars in America 2008."" The main emphasis of the article emphasizes the point that in 2007 1 in every 100 Americans were in prison. To note: Many states have not completed their data verification process. Final published figures may differ slightly. The District of Columbia is not included. D.C. prisoners were transferred to federal custody in 2001

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 type of weapons used in murder offenses. The data are based on the aggregated data from agencies within each state for which supplemental homicide data (i.e., weapon information) were reported to the FBI. The table also includes a breakdown of the types of firearms used in murders (i.e., handguns, rifles, shotguns, or unknown firearms)". "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. Total murders from 2005 and 2004 were also included. Please see the Data Declaration for further information on the data set. Values of -1 represent no value.

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.

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