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 WAS LAST UPDATED AT 2:11 AM EASTERN ON JUNE 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.

These data are part of NACJD's Fast Track Release and are distributed as they were received from the data depositor. The files have been zipped by NACJD for release, but not checked or processed except for the removal of direct identifiers. Users should refer to the accompanying readme file for a brief description of the files available with this collection and consult the investigator(s) if further information is needed. The study constructed a comprehensive, longitudinal dataset of all counties nested within U.S. States from 1970 to 2012. The study's main purpose was to facilitate research that would further understanding on firearm legislation and its impacts on violence. This comprehensive data collection effort included information on firearm legislation implemented across U.S. States over time in combination with multiple measures of firearm-related violence and injury. Moreover, to better understand the conditions under which firearm legislation is more or less effective, incorporation of county characteristics allowed for examination of whether the effectiveness of state-level firearm legislation depends upon particular characteristics of counties. The researchers conducted a secondary analysis utilizing a variety of archived external government and census sources. The Study's Dataset Include two Stata Files: CJRC_firearms_research.dta (95 Variables, 129,027 Cases) state_law_data.dta (19 Variables, 2,168 Cases)

In the United States, gun laws vary from one state to the next; whether residents need a permit or a background check to purchase a firearm, whether residents must undergo firearm training before making this purchase, and whether residents can openly carry their guns in public is dependent upon state legislation. As of 2024, 22 U.S. states required background checks and/or permits for the purchase of a handgun. A further 13 states had regulations on openly carrying firearms in public, however, only California, Connecticut, Florida, and Illinois had completely prohibited open carry for all firearms. In comparison, Maryland, New Jersey, and New York prohibited open carry for handguns but either did not have regulations in place or required a permit for other types of guns. A constitutional right The Second Amendment of the Constitution, which states that citizens have the right to bear arms, has made it difficult for any gun control legislation to be passed on a national level in the United States. As a result, gun control laws in the U.S. are state-based, and often differ based on political perspectives. States with strong gun laws in place, such as Massachusetts, generally experience less gun violence, however, some states with strong gun laws, such as Maryland, continue to face high rates of gun violence, which has largely been attributed to gun trafficking activity found throughout the nation. A culture of gun owners In comparison to other high-income countries with stricter gun control laws, the United States has the highest gun homicide rate at 4.38 gun homicides per 100,000 residents. However, despite increasing evidence that easy access to firearms, whether legal or illegal, encourages higher rates of gun violence, the United States continues to foster an environment in which owning a firearm is seen as a personal freedom. Almost half of U.S. households have reported owning at least one firearm and 43 percent of registered voters in the U.S. were found to believe that it was more important to protect the right of Americans to own guns, compared to 23 percent who said it was more important to limit gun ownership.

This study was undertaken to obtain information on the characteristics of gun ownership, gun-carrying practices, and weapons-related incidents in the United States -- specifically, gun use and other weapons used in self-defense against humans and animals. Data were gathered using a national random-digit-dial telephone survey. The respondents were comprised of 1,905 randomly-selected adults aged 18 and older living in the 50 United States. All interviews were completed between May 28 and July 2, 1996. The sample was designed to be a representative sample of households, not of individuals, so researchers did not interview more than one adult from each household. To start the interview, six qualifying questions were asked, dealing with (1) gun ownership, (2) gun-carrying practices, (3) gun display against the respondent, (4) gun use in self-defense against animals, (5) gun use in self-defense against people, and (6) other weapons used in self-defense. A "yes" response to a qualifying question led to a series of additional questions on the same topic as the qualifying question. Part 1, Survey Data, contains the coded data obtained during the interviews, and Part 2, Open-Ended-Verbatim Responses, consists of the answers to open-ended questions provided by the respondents. Information collected for Part 1 covers how many firearms were owned by household members, types of firearms owned (handguns, revolvers, pistols, fully automatic weapons, and assault weapons), whether the respondent personally owned a gun, reasons for owning a gun, type of gun carried, whether the gun was ever kept loaded, kept concealed, used for personal protection, or used for work, and whether the respondent had a permit to carry the gun. Additional questions focused on incidents in which a gun was displayed in a hostile manner against the respondent, including the number of times such an incident took place, the location of the event in which the gun was displayed against the respondent, whether the police were contacted, whether the individual displaying the gun was known to the respondent, whether the incident was a burglary, robbery, or other planned assault, and the number of shots fired during the incident. Variables concerning gun use by the respondent in self-defense against an animal include the number of times the respondent used a gun in this manner and whether the respondent was hunting at the time of the incident. Other variables in Part 1 deal with gun use in self-defense against people, such as the location of the event, if the other individual knew the respondent had a gun, the type of gun used, any injuries to the respondent or to the individual that required medical attention or hospitalization, whether the incident was reported to the police, whether there were any arrests, whether other weapons were used in self-defense, the type of other weapon used, location of the incident in which the other weapon was used, and whether the respondent was working as a police officer or security guard or was in the military at the time of the event. Demographic variables in Part 1 include the gender, race, age, household income, and type of community (city, suburb, or rural) in which the respondent lived. Open-ended questions asked during the interview comprise the variables in Part 2. Responses include descriptions of where the respondent was when he or she displayed a gun (in self-defense or otherwise), specific reasons why the respondent displayed a gun, how the other individual reacted when the respondent displayed the gun, how the individual knew the respondent had a gun, whether the police were contacted for specific self-defense events, and if not, why not.

description: The Division of Criminal Justice Services (DCJS) collects crime reports from more than 500 New York State police and sheriffs departments. DCJS compiles these reports as New York s official crime statistics and submits them to the FBI under the National Uniform Crime Reporting (UCR) Program. UCR uses standard offense definitions to count crime in localities across America regardless of variations in crime laws from state to state. In New York State, law enforcement agencies use the UCR system to report their monthly crime totals to DCJS. The UCR reporting system collects information on seven crimes classified as Index offenses which are most commonly used to gauge overall crime volume. These include the violent crimes of murder/non-negligent manslaughter, forcible rape, robbery, and aggravated assault; and the property crimes of burglary, larceny, and motor vehicle theft. Firearm counts are derived from taking the number of violent crimes which involve a firearm. Population data are provided every year by the FBI, based on US Census information. Police agencies may experience reporting problems that preclude accurate or complete reporting. The counts represent only crimes reported to the police but not total crimes that occurred.; abstract: The Division of Criminal Justice Services (DCJS) collects crime reports from more than 500 New York State police and sheriffs departments. DCJS compiles these reports as New York s official crime statistics and submits them to the FBI under the National Uniform Crime Reporting (UCR) Program. UCR uses standard offense definitions to count crime in localities across America regardless of variations in crime laws from state to state. In New York State, law enforcement agencies use the UCR system to report their monthly crime totals to DCJS. The UCR reporting system collects information on seven crimes classified as Index offenses which are most commonly used to gauge overall crime volume. These include the violent crimes of murder/non-negligent manslaughter, forcible rape, robbery, and aggravated assault; and the property crimes of burglary, larceny, and motor vehicle theft. Firearm counts are derived from taking the number of violent crimes which involve a firearm. Population data are provided every year by the FBI, based on US Census information. Police agencies may experience reporting problems that preclude accurate or complete reporting. The counts represent only crimes reported to the police but not total crimes that occurred.

This submission includes publicly available data extracted in its original form. Please reference the Related Publication listed here for source and citation information: Centers for Disease Control and Prevention, National Center for Health Statistics. National Vital Statistics System, Mortality 2018-2023 on CDC WONDER Online Database, released in 2024. If you have questions about the underlying data stored here, please call 301-458-4800 or e-mail at paoquery@cdc.gov. If you have questions or recommendations related to this metadata entry and extracted data, please contact the CAFE Data Management team at: climatecafe@bu.edu. "Number of deaths and age-adjusted death rates from firearm-related fatalities. States are categorized from highest rate to lowest rate. Although adjusted for differences in age-distribution and population size, rankings by state do not take into account other state specific population characteristics that may affect the level of mortality. When the number of deaths is small, rankings by state may be unreliable due to instability in death rates." This dataset includes firearms mortality by state and year from 2005 to 2022. Taken from "Stats of the States", NCHS. [Quote from: https://www.cdc.gov/nchs/pressroom/stats_of_the_states.htm]

Context:

The State Firearm Laws project aims to provide researchers with the data necessary to evaluate the effectiveness of various firearm laws. By carefully monitoring how gun legislation impacts firearm-related violence, we can provide policymakers with the evidence they need to make gun ownership safer for everyone.

Ammunition regulations establish rules for anyone in the business of buying or selling firearm ammunition. Federal regulation of firearm ammunition usually accompanies the regulation of firearms, rather than existing independently. For example, the federal age requirements for ammunition purchase, by type of firearm and type of dealer, are the same as those for the purchase of firearms, and the populations that are prohibited from possessing firearms are also prohibited from possessing firearm ammunition.

Content:

Data covers all 50 US States, 1991-2017 and includes:

• Vendor license required to sell ammunition.
• Records of ammunition sales must be retained by the dealer.
• Permit required to purchase ammunition.
• Background checks required for ammunition purchases.
• Sale of ammunition is restricted to the same categories of those who are legally allowed to purchase firearms.
• Purchase of any type of ammunition restricted to those ages 18 and older.
• Purchase of handgun ammunition restricted to those ages 21 and older.

Acknowledgements:

One-hundred of the 133 provisions were coded by Michael Siegel, MD, MPH, Boston University School of Public Health, with funding from the Robert Wood Johnson Foundation, Evidence for Action: Investigator-Initiated Research to Build a Culture of Health program (grant #73337), using data derived from the Thomson Reuters Westlaw legislative database. The other 33 provisions were coded using a database created by Everytown for Gun Safety and Legal Science, LLC. Shared in accordance with the Creative Commons Attribution-4.0 International License, which is incorporated herein by this reference. No changes were made to the original coding, but the data were adapted for use in this database. See the codebook for a list of which provisions were coded by which source. Additional materials include an associated report and related publications.

Inspiration:

• Which states have seen the most increase in regulation? Any decrease?
• Can you correlate gun laws and homicides from this dataset?

This study examines the entire range of case-processing decisions after arrest, from charging to sentencing of firearm-related crimes. This study analyzes the cumulative effects of each decision point, after a charge has been issued, on the subsequent decisions of criminal justice officials. It examines criminal justice decisions regarding a serious category of crime, gun-related offenses. These offenses, most of which are felonious firearm possession or firearm use cases, vary substantially with respect to bail, pretrial detention, and sentencing outcomes (Williams and Rosenfeld, 2016). The focus of this study is St. Louis, where firearm violence is a critical public problem and where neighborhoods range widely in both stability and level of disadvantage. These communities are characterized on the basis of a large number of demographic and socioeconomic indicators. The study aims to enhance understanding of the community context of the criminal justice processing of firearm-related crimes.

This study examined the relationships among trends in deadly gun violence, overall gun availability, and the availability of more lethal types of guns. Using firearms confiscated by the Dallas, Texas, police department from 1980 to 1992 as indicators of the types of guns circulating among criminal/high-risk groups, the project examined changes over time in Dallas' street gun arsenal and assessed the impact these changes had upon gun violence mortality in Dallas. The focus of the project was on the characteristics of the guns rather than their numbers. All confiscated firearms were analyzed and characterized according to basic weapon type and caliber groupings. Dates of confiscation were missing from the majority of the pre-1988 records, but by aggregating the gun data into bimonthly (Part 1) and quarterly (Part 2) time series databases, it was possible to estimate the bimonthly and quarterly periods of confiscation for most of the 1980-1992 records. Records that could not be assigned to bimonthly or quarterly periods were dropped. Confiscated firearms were grouped into basic categories based on stopping power (i.e., wounding potential), rate of fire, and ammunition capacity. The following measures were created for each bimonthly and quarterly period: (1) weapons with high stopping power (large guns), (2) semiautomatic weaponry (semis), (3) weapons combining high stopping power and a semiautomatic firing mechanism (large semis), (4) handguns with high stopping power (large handguns), (5) semiautomatic handguns (semi handguns), and (6) handguns combining high stopping power and semiautomatic firing (large semi handguns). Several violence measures were obtained from the Federal Bureau of Investigation's (FBI) Uniform Crime Reports Supplemental Homicide Reports and Return A (or Offenses Known and Clearances by Arrest) data files (see UNIFORM CRIME REPORTING PROGRAM DATA [UNITED STATES]: 1975-1997 [ICPSR 9028]). These measures were also aggregated at bimonthly and quarterly levels. Data from the Dallas Police Department master gun property file include total handguns, total semiautomatic handguns, total large-caliber handguns, total large-caliber semiautomatic handguns, total shotguns, total semiautomatic shotguns, total rifles, total semiautomatic rifles, and total counts and total semiautomatic counts for various calibers of handguns, shotguns, and rifles. Data that were aggregated using the FBI data include total homicides, gun homicides, total robberies, gun robberies, and gun aggravated assaults. The data file also includes the year and the bimonthly or quarterly period counter.

In 1985, the Teens, Crime, and the Community and Community Works (TCC/CW) program, a collaborative effort by the National Crime Prevention Council (NCPC) and Street Law, Inc., was developed in an effort to reduce adolescent victimization. The purpose of the study was to assess whether the TCC/CW program was successfully implemented and whether it achieved its desired outcome, namely to reduce adolescent victimization. Following an extensive effort to identify potential sites for inclusion in the TCC/CW program outcome evaluation, a quasi-experimental five-wave panel study of public school students was initiated in the fall of 2004. Classrooms in the sample were matched by teacher or subject and one-half of the classrooms received the TCC/CW curriculum while the other half (the control group) was not exposed to the curriculum. A total of 1,686 students representing 98 classrooms in 15 middle schools located in 9 cities in 4 different states were surveyed 3 times: pre-tests in Fall 2004 (Part 1), post-tests in Spring 2005 (Part 2), and through a one-year follow-up survey in Fall 2005 (Part 3). A total of 227 variables are included in Part 1, 297 in Part 2, and 290 in Part 3. Most of these variables are the same across waves, including demographic variables, variables measuring whether the students are involved in extracurricular and other school related activities, community service, religious activities, family activities, employment, or illegal activities and crime, variables measuring the students' views regarding bullying, schoolwork, school and neighborhood violence, property crimes, drug use, alcohol use, gun violence, vandalism, skipping school, inter-racial tensions, neighborhood poverty, and law-enforcement officers, variables measuring how students react to anger, risk, conflict with fellow students, and how they handle long-term versus short-term decision-making, variables measuring group dynamics, variables measuring students' self-esteem, and variables measuring students' awareness of resources in their respective school and neighborhood to address problems and provide support.

This study of violent incidents among middle- and high-school students focused not only on the types and frequency of these incidents, but also on their dynamics -- the locations, the opening moves, the relationship between the disputants, the goals and justifications of the aggressor, the role of third parties, and other factors. For this study, violence was defined as an act carried out with the intention, or perceived intention, of physically injuring another person, and the "opening move" was defined as the action of a respondent, antagonist, or third party that was viewed as beginning the violent incident. Data were obtained from interviews with 70 boys and 40 girls who attended public schools with populations that had high rates of violence. About half of the students came from a middle school in an economically disadvantaged African-American section of a large southern city. The neighborhood the school served, which included a public housing project, had some of the country's highest rates of reported violent crime. The other half of the sample were volunteers from an alternative high school attended by students who had committed serious violations of school rules, largely involving illegal drugs, possession of handguns, or fighting. Many students in this high school, which is located in a large city in the southern part of the Midwest, came from high-crime areas, including public housing communities. The interviews were open-ended, with the students encouraged to speak at length about any violent incidents in school, at home, or in the neighborhood in which they had been involved. The 110 interviews yielded 250 incidents and are presented as text files, Parts 3 and 4. The interview transcriptions were then reduced to a quantitative database with the incident as the unit of analysis (Part 1). Incidents were diagrammed, and events in each sequence were coded and grouped to show the typical patterns and sub-patterns in the interactions. Explanations the students offered for the violent-incident behavior were grouped into two categories: (1) "justifications," in which the young people accepted responsibility for their violent actions but denied that the actions were wrong, and (2) "excuses," in which the young people admitted the act was wrong but denied responsibility. Every case in the incident database had at least one physical indicator of force or violence. The respondent-level file (Part 2) was created from the incident-level file using the AGGREGATE procedure in SPSS. Variables in Part 1 include the sex, grade, and age of the respondent, the sex and estimated age of the antagonist, the relationship between respondent and antagonist, the nature and _location of the opening move, the respondent's response to the opening move, persons present during the incident, the respondent's emotions during the incident, the person who ended the fight, punishments imposed due to the incident, whether the respondent was arrested, and the duration of the incident. Additional items cover the number of times during the incident that something was thrown, the respondent was pushed, slapped, or spanked, was kicked, bit, or hit with a fist or with something else, was beaten up, cut, or bruised, was threatened with a knife or gun, or a knife or gun was used on the respondent. Variables in Part 2 include the respondent's age, gender, race, and grade at the time of the interview, the number of incidents per respondent, if the respondent was an armed robber or a victim of an armed robbery, and whether the respondent had something thrown at him/her, was pushed, slapped, or spanked, was kicked, bit, or hit with a fist or with something else, was beaten up, was threatened with a knife or gun, or had a knife or gun used on him/her.

Analysis of ‘Index, Violent, Property, and Firearm Rates By County: Beginning 1990’ provided by Analyst-2 (analyst-2.ai), based on source dataset retrieved from https://catalog.data.gov/dataset/9c9619a6-a7cc-48f7-aefb-cb5c77327b9c on 27 January 2022.

--- Dataset description provided by original source is as follows ---

The Division of Criminal Justice Services (DCJS) collects crime reports from more than 500 New York State police and sheriffs’ departments. DCJS compiles these reports as New York’s official crime statistics and submits them to the FBI under the National Uniform Crime Reporting (UCR) Program. UCR uses standard offense definitions to count crime in localities across America regardless of variations in crime laws from state to state. In New York State, law enforcement agencies use the UCR system to report their monthly crime totals to DCJS. The UCR reporting system collects information on seven crimes classified as Index offenses which are most commonly used to gauge overall crime volume. These include the violent crimes of murder/non-negligent manslaughter, forcible rape, robbery, and aggravated assault; and the property crimes of burglary, larceny, and motor vehicle theft. Firearm counts are derived from taking the number of violent crimes which involve a firearm. Population data are provided every year by the FBI, based on US Census information. Police agencies may experience reporting problems that preclude accurate or complete reporting. The counts represent only crimes reported to the police but not total crimes that occurred. DCJS posts preliminary data in the spring and final data in the fall.

--- Original source retains full ownership of the source dataset ---

IntroductionFor over two decades school shootings have become a significant concern, especially in the United States. Following a rampage school shooting, extensive resources are devoted to gathering all of the information surrounding the event. To date, few studies have compared completed to averted, or near-miss, school shootings. This study utilized the largest known sample of cases based in the United States in an effort to identify potential targets for prevention.MethodData were derived from the Averted School Violence database of incidents occurring between 1999 and 2020. Statistical analyses were conducted to determine how age, co-conspirator involvement, engagement in leakage warning behavior, and motives – in isolation and in combination – varied between groups.ResultsIn insolation, age, co-conspirator involvement, engagement in leakage warning behaviors, and motives were significantly different between groups. However, when these variables were combined into a logistic regression, co-conspirator involvement, engagement in leakage warning behaviors, and motives involving suicidal intent emerged as statistically significant predictors of group membership. Age no longer differentiated the two types of events.ConclusionThis study demonstrates that regardless of suspect age, threats of school violence must be taken seriously and investigated fully. Further, students reporting their peers’ engagement in shooting-related behaviors (e.g., bringing a gun to school, mapping school, etc.) was one of the most significant predictors that a plot will be thwarted. While perpetrators who planned with others had increased odds of their plot being identified, those acting alone still demonstrated leakage behaviors. If individuals in the school environment are educated regarding warning behaviors, lone perpetrators can still be identified and reported to authorities. The perpetrator’s emotional distress, in particular depressive or suicidal thoughts were also a significant predictor of a completed school shooting. Future research efforts should focus on the development and evaluation of peer training programs to assist in the detection of school shooting warning behaviors.

This is historical data. The update frequency has been set to "Static Data" and is here for historic value. Updated on 8/14/2024 Drug-Induced Death Rate - This indicator shows the drug-induced death rate per 100,000 population. Drug-induced deaths include all deaths for which illicit or prescription drugs are the underlying cause. In 2007, drug-induced deaths were more common than alcohol-induced or firearm-related deaths in the United States. Between 2012-2014, there were 2793 drug-induced deaths in Maryland. Link to Data Details