THIS DATASET WAS LAST UPDATED AT 8:11 PM EASTERN ON OCT. 13

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 National Violent Death Reporting System (NVDRS) provides states and communities with a clearer understanding of violent deaths to guide local decisions about efforts to prevent violence and helps them track progress over time. To stop violent deaths, we must first understand all the facts. Created in 2002, the NVDRS is a surveillance system that pulls together data on violent deaths in 18 states (see map below), including information about homicides, such as homicides perpetrated by a intimate partner (e.g., boyfriend, girlfriend, wife, husband), child maltreatment (or child abuse) fatalities, suicides, deaths where individuals are killed by law enforcement in the line of duty, unintentional firearm injury deaths, and deaths of undetermined intent. These data are supported by WISQARS, an interactive query system that provides data on injury deaths, violent deaths, and nonfatal injuries.

The Gun Violence Archive (GVA) is an online archive of gun violence incidents collected from over 7,500 law enforcement, media, government and commercial sources daily in an effort to provide near-real time data about the results of gun violence. GVA was established in 2013 an independent data collection and research group to provide comprehensive data for the national conversation regarding gun violence.

GVA catalogs both incidents of gun-related deaths and incidents where a victim was injured by shooting or by a victim who was the subject of an armed robber or home invader. Incidents of defensive gun use, homeowners who stop a home invasion, store clerks who stop a robbery, individuals who stop an assault or rape with a gun are also collected. The two exceptions to the near real-time collection are suicides by gun, which are collected quarterly and annually due to differing distribution methods by government agencies, and for armed robberies with no injuries or DGU characteristics, which are collected in aggregate with law enforcement quarterly and annual reports. GVA also records incidents of Bureau of Alcohol, Tobacco, Firearms, and Explosives (ATF) and local law enforcement involvement in recovering illegal or stolen weapons; incidents where guns were reported stolen from homes, vehicles, and businesses; incidents where Airsoft or BB guns are used as weapons (but not where they are used in general vandalism or delinquency); and TSA data of guns illegally taken through airport security points. Incident data are categorized by number of deaths, number of injuries, number of children, number of teens, mass shootings, officers shot, suspect shot by officer, home invasion, defensive use, and unintentional shooting.

This dataset was collected from the Children's Defense Fund website. The data come from the "Protect Children, Not Guns" Reports from years 2007, 2004 and 2000. They include data on deaths of children from firearms due to homicide, suicide, accident, and undetermined intent from 1996 to 2004 by state. Sources: U.S. Department of Health and Human Services, National Center for Health Statistics, Table III: Deaths from # selected causes, and U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Center for Injury Prevention and Control, WISQARS, at http://www.cdc.gov/ncipc/wisqars/ [2001]. Calculations by the Childrens Defense Fund.

Trend of firearm mortality after legislation.

This file contains death counts and death rates for drug overdose, suicide, homicide and firearm injuries by census tract of residence (additional datasets exist for other levels of geography). The data is grouped by 2 different time periods including yearly and trailing twelve months. Please see data dictionary for intents and mechanisms included in each measure.

When there are 1-9 deaths in an area, CDC uses a Bayesian model to calculate rates. A Bayesian model is a type of statistical model often used in geographic analysis. This model can improve stability of the rates in lower population areas and protects privacy by taking into account information from neighboring areas.

Rate ratio of the post effect trends of suicide by hanging and firearms.

Risk associated between firearm prevalence and suicide rates.

This file contains death counts and death rates for drug overdose, suicide, homicide and firearm injuries by county of residence (additional datasets exist for other levels of geography). The data is grouped by 2 different time periods including yearly and trailing twelve months. Please see data dictionary for intents and mechanisms included in each measure.

When there are 1-9 deaths in an area, CDC uses a Bayesian model to calculate rates. A Bayesian model is a type of statistical model often used in geographic analysis. This model can improve stability of the rates in lower population areas and protects privacy by taking into account information from neighboring areas.

The Toronto’s Police Service Annual Statistical Report (ASR) is a comprehensive overview of police related statistics including reported crimes, victims of crime, search of persons, firearms, traffic collisions, personnel, budget, communications, public complaints, regulated interactions and other administrative information. This dataset includes all shooting occurrences from 2014 to 2019 by occurred date aggregated by Division. This data includes all shooting-related events reported to the Toronto Police Service, including, but not limited to, those that may have been deemed unfounded after investigation. Data is accurate as of the date and time of reporting. In accordance with the Municipal Freedom of Information and Protection of Privacy Act, the Toronto Police Service has taken the necessary measures to protect the privacy of individuals involved in the reported occurrences. No personal information related to any of the parties involved in the occurrence will be released as open data. The data has been aggregated by year, category, subtype and geographic division. As there is no criminal offence code for shootings, a shooting occurrence number may also be present in other data sets including, but not limited to, assault and robbery. Note: The further breakdown of this information at the event level will be made available in the future releases of the Shootings open data. Shootings in this data set include both firearm discharges and shooting events, which are defined as follows: Shooting Event/Occurrence: Any incident in which a projectile is discharged from a firearm (as defined under the Criminal Code of Canada) and injures a person. This excludes events such as suicide and police involved firearm discharges. Firearm Discharge: Any incident where evidence exists that a projectile was discharged from a firearm (as defined under the Criminal Code of Canada) including accidental discharge (non-police), celebratory fire, drive-by etc. Persons Injured (previously classified as “victims”): A person who was struck by a bullet(s) as a result of the discharge of a firearm (as defined under the Criminal Code of Canada). This excludes events such as suicide, police-involved event or where the weapon used was not a real firearm (such as pellet gun, air pistol, “sim-munition” etc.) Injury Levels Death: Where the injured person (as defined above) has died as a result of injuries sustained from a bullet(s). Injuries: Where the injured person (as defined above) has non-fatal physical injuries as a result of a bullet(s). This data is related to table (ASR-SH-TBL-001) in The Annual Statistical Report. Additional information can be found here.

This dataset examines the number of unidentified persons reported to the Centers for Disease Control and Preventions (CDC) National Death Index (NDI), by State, from 1980 to 2004. This report also looks at the number of unidentified human remains reported to the Federal Bureau of Investigations (FBI) National Crime Information Center (NCIC) Unidentified Person File. It describes the characteristics by race and gender and the manner of death. Highlights include the following: Between 1980 and 2004, about 10,300 unidentified human remains were reported to the National Death Index (NDI). Almost three-quarters of unidentified persons were reported by 5 states; Arizona, California, Florida, New York, and Texas. Of the 2,900 National Crime Information Center records that contained data on the manner of death, 27% were ruled homicides; 12%, accidental deaths; 7%, natural causes; and 5%, suicides. The majority of unidentified persons were white (70%); blacks made up 15% of unidentified persons; and race could not be determined in 13% of the cases. For more information about this data go to: http://www.ojp.usdoj.gov/bjs/abstract/uhrus04.htm

Prevalence of a suicide note and other selected psychological/psychiatric characteristics documented in drug intoxication and gunshot/hanging suicide and undetermined death cases: 17 National Violent Death Reporting System states, 2011–2013.

BackgroundFirearm-related suicide is the second leading cause of pediatric firearm death. Lethal means counseling (LMC) can improve firearm safe-storage practices for families with youth at risk of suicide.ObjectivesThis study aims to evaluate the feasibility of pediatric emergency department (ED) behavioral mental health (BMH) specialists providing LMC to caregivers of youth presenting with BMH complaints and to test for changes in firearm safety practices, pre-post ED LMC intervention, as measures of preliminary efficacy.MethodsProspective pilot feasibility study of caregivers of youth presenting to a pediatric ED with BMH complaints. Caregivers completed an electronic survey regarding demographics and firearm safe-storage knowledge/practices followed by BMH specialist LMC. Firearm owners were offered a free lockbox and/or trigger lock. One-week follow-up surveys gathered self-reported data on firearm safety practices and intervention acceptability. One-month interviews with randomly sampled firearm owners collected additional firearm safety data. Primary outcomes were feasibility measures, including participant accrual/attrition and LMC intervention acceptability. Secondary outcomes included self-reported firearm safety practice changes. Feasibility benchmarks were manually tabulated, and Likert-scale acceptability responses were dichotomized to strongly agree/agree vs. neutral/disagree/strongly disagree. Descriptive statistics were used for univariate and paired data responses.ResultsIn total, 81 caregivers were approached; of which, 50 (81%) caregivers enrolled. A total of 44% reported having a firearm at home, 80% completed follow-up at 1- week. More than 80% affirmed that ED firearm safety education was useful and that the ED is an appropriate place for firearm safety discussions. In total, 58% of participants reported not having prior firearm safety education/counseling. Among firearm owners (n = 22), 18% reported rarely/never previously using a safe-storage device, and 59% of firearm owners requested safe storage devices.At 1-week follow-up (n = 40), a greater proportion of caregivers self-reported asking about firearms before their child visited other homes (+28%). Among firearm owners that completed follow-up (n = 19), 100% reported storing all firearms locked at 1-week (+23% post-intervention). In total, 10 caregivers reported temporarily/permanently removing firearms from the home.ConclusionIt is feasible to provide LMC in the pediatric ED via BMH specialists to families of high-risk youth. Caregivers were receptive to LMC and reported finding this intervention useful, acceptable, and appropriate. Additionally, LMC and device distribution led to reported changes in safe storage practices.

Changes in suicide methods by sex and age group over the period 1995 to 2019 (baseline: 1995–1999).