Texas was the state with the highest number of registered weapons in the United States in 2024, with 1,136,732 firearms. Rhode Island, on the other hand, had the least, with 4,895 registered firearms. Gun laws in the United States Gun ownership in the U.S. is protected by the 2nd Amendment of the Constitution, which allows citizens to own firearms and form a militia if necessary. Outside of the 2nd Amendment, gun laws in the U.S. vary from state to state, and gun owners are subject to the laws of the state they are currently in, not necessarily the state they live in. For example, if concealed carry is allowed in a gun owner’s state of residence but not in the state they are traveling in, the owner is subject to the law of the state they are traveling in. Civilian-owned firearms The United States is estimated to have the highest rate of civilian-owned firearms in the world, more than double that of Yemen, which has the second-highest gun ownership rate. Unfortunately, along with high gun ownership rates comes a higher number of homicides by firearm, which was about 13,529 homicides in 2023.

Introduction: Firearm legality and ownership have been contentious topics in American culture, due to the well-documented, yet preventable, health and safety risks. States vary in the amount of firearm ownership, as well as firearm mortality and injury rates. Objectives: The primary aim of this project is to compare two states, New Jersey and Texas, on the likelihood of firearm violence occurring to each state's citizens. The variables of gun ownership, firearm mortalities, and firearm injuries are compared and visualized to understand if living in one state is safer than living in the other. Methods: Data analysis focused on connecting and comparing the two states with variables pointing to firearm safety/danger. Line graphs compare the two states and firearm injuries and mortalities over a sixteen-year period as well as number of firearms per state. Scatterplots show a correlation, if any, between number of firearms and injuries/mortalities in the two states. Results: Texas had a consistently higher mortality rate by firearms (excluding suicides) for each year of the seventeen years. Texas also led in firearm injuries from the years 2000-2010, 2012, and 2014-2016, but not in 2011 and 2013. New Jersey consistently has a lower mortality rate (3.5 and under per 100,000) and lower gun ownership (.11 and under per household). Texas’ data has both a higher mortality rate (between 3.8 and 4.8 per 100,000) and a higher gun ownership rate (.34 to .40 per household). With a few exceptions from the years 2011 and 2013, the state data points are clustered to show the relationship between gun ownership and firearm injuries to be high/high for Texas and low/low for New Jersey. Conclusions: From the years 2000-2016 it is, on average, 20% less likely that one will be injured by a firearm and 30% less likely that one will be killed by a firearm if one were to live in New Jersey instead of Texas, causing the conclusion that it is safer to live in New Jersey than in Texas.

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 January 15, 2025, ** U.S. states required background checks and/or permits for the purchase of a handgun. A further ** 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 **** 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 personal freedom. Almost **** of U.S. households have reported owning at least one firearm and ** 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 ** percent who said it was more important to limit gun ownership.

The share of American households owning at least one firearm has remained relatively steady since 1972, hovering between ** percent and ** percent. In 2024, about ** percent of U.S. households had at least one gun in their possession. Additional information on firearms in the United States Firearms command a higher degree of cultural significance in the United States than any other country in the world. Since the inclusion of the right to bear arms in the Second Amendment to the Constitution of the United States, firearms have held symbolic power beyond their already obvious material power. Despite many Americans being proud gun-owners, a large movement exists within the country in opposition to the freedom afforded to those in possession of these potentially deadly weapons. Those opposed to current gun regulation have sourced their anger from the large number of deaths due to firearms in the country, as well as the high frequency of gun violence apparent in comparison to other developed countries. Furthermore, the United States has fallen victim to a number of mass shootings in the last two decades, most of which have raised questions over the ease at which a person can obtain a firearm. Although this movement holds a significant position in the public political discourse of the United States, meaningful change regarding the legislation dictating the ownership of firearms has not occurred. Critics have pointed to the influence possessed by the National Rifle Association through their lobbying of public officials. The National Rifle Association also lobbies for the interests of firearm manufacturing in the United States, which has continued to rise since a fall in the early 2000s.

The State Firearm Database catalogs the presence or absence of 134 firearm safety laws in 14 categories covering the 26-year period from 1991 to 2019. The classification system categorizes state firearm provisions using a methodology that both captures differences and maintains a level of comparability between states. Because of this, the database is not the most detailed nor the most comprehensive record of all state firearm policies. Other resources may provide users with a deeper understanding of individual provisions, while this database serves as an efficient way to compare the broad scope of state firearm laws across the country. These provisions covered 14 aspects of state policies, including regulation of the process by which firearm transfers take place, ammunition, firearm possession, firearm storage, firearm trafficking, and liability of firearm manufacturers. In addition, descriptions of the criteria used to code each provision have been provided so that there is transparency in how various law exemptions, exceptions, and other nuances were addressed.

This nationally representative, anonymous, household telephone survey was conducted to explore the distribution of privately owned firearms in the United States, as well as firearm acquisition, disposal, and storage in households with guns. The study updates an earlier (1994) study by Cook and Ludwig that examined household firearm ownership in the United States (Cook P.J., Ludwig J. Guns in America: Results of a comprehensive national survey of firearms ownership and use. Washington DC: Police Foundation 1997.) Other domains of the survey included (1) past year firearm use both by respondents with firearms in their households and those without (e.g., "In the past 12 months, have you handled any gun"); (2) guns and youth (e.g., "In the last 12 months, have you ever asked another parent whether their home contains guns?"); (3) awareness of and opinions regarding state and federal firearm laws (e.g., "To the best of your knowledge, does your state have a law that holds adults liable for misuse of their guns by children or minors"; "Do you favor or oppose the sale of military style firearms?"); (4) depression and suicide (e.g., "If the Golden Gate Bridge had a barrier to prevent suicide, about how many of the 1,000 jumpers (who have committed suicide by jumping off the bridge since 1937) do you think would have found some other way to kill themselves?") and (5) aggressive driving (e.g., "In the past 12 months, have you made obscene or rude gestures at another motorist"). The survey also included extensive demographic information about the respondent and his or her family. The demographic information that was collected includes respondents' sex, age, race, education level, household income, criminal arrest history, armed forces membership status, type of residential area (e.g., urban or rural), and political philosophy.

State-level firearm suicide proxy (FSS) for household gun ownership 1949-2020. Unlike most gun prevalence measures that are representative at the national or regional level, this proxy represents household gun ownership trends at the state level and is not reliant on self-reported data that are prone to social desirability bias. This extended proxy represents the longest-ranging dataset of state-level gun ownership rates to date. This dataset also includes historic data on firearm homicide and homicide counts and rates per 100,000 residents.

The State Alcohol-Related Firearm Statutes (SARFS) dataset was developed to analyze statutes that aim to prevent or regulate firearm access by individuals who are either acutely intoxicated or have alcohol misuse history (“alcohol-related firearm laws”) from all 50 states and to examine their impact on firearm-related injuries and mortality. This dataset contains numerical variables that describe enactment, amendment, and repeal (if applicable) of alcohol-related firearm laws during the years of 2010 to 2023.The methods used to perform the original legal research followed a pre-published protocol: Silver D, Bae J, Macinko J. Protocol for creating a dataset of US state alcohol-related firearm laws 2000–2022. PLoS one. 2024 Mar 7;19(3):e029924. In brief, the most up-to-date version of statutes were collected from Westlaw, a proprietary online legal research database, beginning with the following broad search terms applied to the entirety of the state statutory codes: [(influence intoxicat! drunk! alcohol) /50 firearm] and [(influence intoxicat! drunk! alcohol) /50 gun]. Utilizing the legislative history summary provided by Westlaw and its historical database, any bills that enacted, amended, or repealed the statutes from 2010 to 2023 as well as court decisions enjoining the laws from going into effect (temporary or permanent) were also obtained. All texts were reviewed and key provisions were coded as separate variables. Each calendar year constitutes a separate sheet in the file, containing variables representing the laws as of that time of 50 states. Any substantive modifications of existing laws were coded as new events with their effective dates specified. Additional Westlaw research was conducted to retrieve penalties and other relevant factors.

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)

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 DATASET WAS LAST UPDATED AT 7:11 AM EASTERN ON DEC. 1

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.

This study examined spatial and temporal features of crime guns in Pittsburgh, Pennsylvania, in order to ascertain how gun availability affected criminal behavior among youth, whether the effects differed between young adults and juveniles, and whether that relationship changed over time. Rather than investigating the general prevalence of guns, this study focused only on those firearms used in the commission of crimes. Crime guns were defined specifically as those used in murders, assaults, robberies, weapons offenses, and drug offenses. The emphasis of the project was on the attributes of crime guns and those who possess them, the geographic sources of those guns, the distribution of crime guns over neighborhoods in a city, and the relationship between the prevalence of crime guns and the incidence of homicide. Data for Part 1, Traced Guns Data, came from the City of Pittsburgh Bureau of Police. Gun trace data provided a detailed view of crime guns recovered by police during a two-year period, from 1995 to 1997. These data identified the original source of each crime gun (first sale to a non-FFL, i.e., a person not holding a Federal Firearms License) as well as attributes of the gun and the person possessing the gun at the time of the precipitating crime, and the ZIP-code location where the gun was recovered. For Part 2, Crime Laboratory Data, data were gathered from the local county crime laboratory on guns submitted by Pittsburgh police for forensic testing. These data were from 1993 to 1998 and provided a longer time series for examining changes in crime guns over time than the data in Part 1. In Parts 3 and 4, Stolen Guns by ZIP-Code Data and Stolen Guns by Census Tract Data, data on stolen guns came from the local police. These data included the attributes of the guns and residential neighborhoods of owners. Part 3 contains data from 1987 to 1996 organized by ZIP code, whereas Part 4 contains data from 1993 to 1996 organized by census tract. Part 5, Shots Fired Data, contains the final indicator of crime gun prevalence for this study, which was 911 calls of incidents involving shots fired. These data provided vital information on both the geographic location and timing of these incidents. Shots-fired incidents not only captured varying levels of access to crime guns, but also variations in the willingness to actually use crime guns in a criminal manner. Part 6, Homicide Data, contains homicide data for the city of Pittsburgh from 1990 to 1995. These data were used to examine the relationship between varying levels of crime gun prevalence and levels of homicide, especially youth homicide, in the same city. Part 7, Pilot Mapping Application, is a pilot application illustrating the potential uses of mapping tools in police investigations of crime guns traced back to original point of sale. NTC. It consists of two ArcView 3.1 project files and 90 supporting data and mapping files. Variables in Part 1 include date of manufacture and sale of the crime gun, weapon type, gun model, caliber, firing mechanism, dealer location (ZIP code and state), recovery date and location (ZIP code and state), age and state of residence of purchaser and possessor, and possessor role. Part 2 also contains gun type and model, as well as gun make, precipitating offense, police zone submitting the gun, and year the gun was submitted to the crime lab. Variables in Parts 3 and 4 include month and year the gun was stolen, gun type, make, and caliber, and owner residence. Residence locations are limited to owner ZIP code in Part 3, and 1990 Census tract number and neighborhood name in Part 4. Part 5 contains the date, time, census tract and police zone of 911 calls relating to shots fired. Part 6 contains the date and census tract of the homicide incident, drug involvement, gang involvement, weapon, and victim and offender ages. Data in Part 7 include state, county, and ZIP code of traced guns, population figures, and counts of crime guns recovered at various geographic locations (states, counties, and ZIP codes) where the traced guns first originated in sales by an FFL to a non-FFL individual. Data for individual guns are not provided in Part 7.

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.

This dataset includes annotations for shooters (both person and visible portion of the gun) and guns in a primarily indoor setting. The synthetic data was generated using Unreal Engine 4 and Unreal Engine 5 and contains both the default semi-realistic textures of the environments and segmentation masks as a form of domain randomization. The textured synthetic data was further augmented with camera sensor effects as another domain adaptation technique. The folders use the following notation: T denotes textured synthetic, M denotes masked synthetic, R denotes real, and the prefix A denotes augmented. We also include some annotated videos for evaluating tracking performance.

The Concealed Carry Weapons License Database (CCWLD) is a longitudinal collection of state and county-level data on concealed carry weapons licenses (CCWs). Data were collected from a series of internet searches and freedom of information requests sent to state governments during the fall of 2019 and winter of 2020. Data cleaning was conducted by research assistants and by Trent Steidley in the winter of 2021.Documentation memos for each state are provided in the archived files. Along with raw data files, Stata syntax for cleaning, and the final cleaned database.This database was supported with funding from the Center on American Politics at the University of Denver and a Professional Research Opportunity for Faculty (PROF) grant from the University of Denver. If you use these data in your research please cite them appropriately.

BackgroundPrior research suggests that United States governmental sources documenting the number of law-enforcement-related deaths (i.e., fatalities due to injuries inflicted by law enforcement officers) undercount these incidents. The National Vital Statistics System (NVSS), administered by the federal government and based on state death certificate data, identifies such deaths by assigning them diagnostic codes corresponding to “legal intervention” in accordance with the International Classification of Diseases–10th Revision (ICD-10). Newer, nongovernmental databases track law-enforcement-related deaths by compiling news media reports and provide an opportunity to assess the magnitude and determinants of suspected NVSS underreporting. Our a priori hypotheses were that underreporting by the NVSS would exceed that by the news media sources, and that underreporting rates would be higher for decedents of color versus white, decedents in lower versus higher income counties, decedents killed by non-firearm (e.g., Taser) versus firearm mechanisms, and deaths recorded by a medical examiner versus coroner.Methods and findingsWe created a new US-wide dataset by matching cases reported in a nongovernmental, news-media-based dataset produced by the newspaper The Guardian, The Counted, to identifiable NVSS mortality records for 2015. We conducted 2 main analyses for this cross-sectional study: (1) an estimate of the total number of deaths and the proportion unreported by each source using capture–recapture analysis and (2) an assessment of correlates of underreporting of law-enforcement-related deaths (demographic characteristics of the decedent, mechanism of death, death investigator type [medical examiner versus coroner], county median income, and county urbanicity) in the NVSS using multilevel logistic regression. We estimated that the total number of law-enforcement-related deaths in 2015 was 1,166 (95% CI: 1,153, 1,184). There were 599 deaths reported in The Counted only, 36 reported in the NVSS only, 487 reported in both lists, and an estimated 44 (95% CI: 31, 62) not reported in either source. The NVSS documented 44.9% (95% CI: 44.2%, 45.4%) of the total number of deaths, and The Counted documented 93.1% (95% CI: 91.7%, 94.2%). In a multivariable mixed-effects logistic model that controlled for all individual- and county-level covariates, decedents injured by non-firearm mechanisms had higher odds of underreporting in the NVSS than those injured by firearms (odds ratio [OR]: 68.2; 95% CI: 15.7, 297.5; p < 0.01), and underreporting was also more likely outside of the highest-income-quintile counties (OR for the lowest versus highest income quintile: 10.1; 95% CI: 2.4, 42.8; p < 0.01). There was no statistically significant difference in the odds of underreporting in the NVSS for deaths certified by coroners compared to medical examiners, and the odds of underreporting did not vary by race/ethnicity. One limitation of our analyses is that we were unable to examine the characteristics of cases that were unreported in The Counted.ConclusionsThe media-based source, The Counted, reported a considerably higher proportion of law-enforcement-related deaths than the NVSS, which failed to report a majority of these incidents. For the NVSS, rates of underreporting were higher in lower income counties and for decedents killed by non-firearm mechanisms. There was no evidence suggesting that underreporting varied by death investigator type (medical examiner versus coroner) or race/ethnicity.

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. This study examines the increase in firearm background checks and the increase in firearm transfer and permit application denials. The study is a secondary analysis, primarily of data already available through public sources. Distributed here are the code used for the secondary analysis and the data not otherwise available through other public means. Please refer to the readme file, distributed with this study, for a list of instructions on how to obtain all other data used in this study.

Comprehensive dataset containing 2 verified Firearms academy businesses in State of Rio de Janeiro, Brazil with complete contact information, ratings, reviews, and location data.

BackgroundSeveral past studies have found that media reports of suicides and homicides appear to subsequently increase the incidence of similar events in the community, apparently due to the coverage planting the seeds of ideation in at-risk individuals to commit similar acts.MethodsHere we explore whether or not contagion is evident in more high-profile incidents, such as school shootings and mass killings (incidents with four or more people killed). We fit a contagion model to recent data sets related to such incidents in the US, with terms that take into account the fact that a school shooting or mass murder may temporarily increase the probability of a similar event in the immediate future, by assuming an exponential decay in contagiousness after an event.ConclusionsWe find significant evidence that mass killings involving firearms are incented by similar events in the immediate past. On average, this temporary increase in probability lasts 13 days, and each incident incites at least 0.30 new incidents (p = 0.0015). We also find significant evidence of contagion in school shootings, for which an incident is contagious for an average of 13 days, and incites an average of at least 0.22 new incidents (p = 0.0001). All p-values are assessed based on a likelihood ratio test comparing the likelihood of a contagion model to that of a null model with no contagion. On average, mass killings involving firearms occur approximately every two weeks in the US, while school shootings occur on average monthly. We find that state prevalence of firearm ownership is significantly associated with the state incidence of mass killings with firearms, school shootings, and mass shootings.

EDFacts Safe and Drug-Free Schools, 2010-11 (EDFacts SDFS:2010-11), is one of 17 'topics' identified in the EDFacts documentation (in this database, each 'topic' is entered as a separate study); program data is available since 2005 at