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.

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.

Number and percentage of homicide victims, by type of firearm used to commit the homicide (total firearms; handgun; rifle or shotgun; other firearm-like weapons; firearm, type of firearm is unknown), Canada, 1974 to 2024.

This dataset looks at firearm restrictions across the USA by state. If a state has a restriction on a certain weapon than possession is prohibited or allowed only under limited exceptions, or there is a registration requirement. Surveyed Weapons: Assault weapon: A semiautomatic firearm with a large-capacity magazine and special features common to military weapons. Machine gun: (automatic firearm) A firearm that shoots, is designed to shoot, or can be readily restored to shoot, automatically more than one bullet, without manual reloading, by a single function of the trigger. Short-barreled rifle: A rifle having one or more barrels less than 16 inches in length, and any weapon made from a rifle, whether by alteration, modification, or otherwise, if such weapon, as modified, has an overall length of less than 26 inches. Short-barreled shotgun: A shotgun having one or more barrels less than 18 inches in length, and any weapon made from a shotgun, whether altered or modified, if such weapon has an overall length of less then 26 inches. Unsafe handgun: (Saturday night special or junk gun) A handgun with a barrel length under 4 inches that is easily concealable and not effective for sporting or self defense purposes due to its poor quality of construction, inaccuracy, and lack of essential safety features. Definitions are from or adapted from Federal and State Codes (a jurisdictions laws should be consulted for specific definitions). This data comes from Survey of State Procedures Related to Firearm Transfers, 2005. The Survey provides an overview of the firearm check procedures in each State and State interaction with the National Instant Criminal Background Check System (NICS) operated by the FBI. The report summarizes issues about State procedures, including persons prohibited from purchasing firearms, restoration of rights of purchase to prohibited persons, permits, prohibited firearms, waiting periods, fees, and appeals.

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.

This dataset displays the participation of each state in the National Instant Criminal Background Check System (NICS) in the USA as of 12.31.2005. The NICS is a point-of-sale system for determining eligibility to purchase a firearm in the USA. Federal Firearms License holders are required by law to use the NICS to determine if it is legal to sell a firearm to a prospective buyer. The NICS determines if the buyer is prohibited from buying a firearm under the Gun Control Act of 1968. The NICS is applicable to sales from federally licensed dealers. Sales of firearms by private sellers are allowed to proceed without a background check unless required by state law. These regulations remain in place at gun shows, where no special leniency is granted to licensed sellers, and no additional requirements are placed upon private sellers. Each State determines the extent of its participation in the NICS process. Three basic forms of State involvement currently exist: 1. a POC requests a NICS check on all firearm transfers originating in the State; 2. a POC requests a NICS check on all handgun transfers; licensees in the State are required to contact the FBI for approval of long gun transfers; or 3. the State does not maintain a point of contact; licensees are required to contact the FBI for NICS checks on all firearm transfers originating in the State. The FBI and the POC agencies always check three major Federal databases, the National Crime Information Center (NCIC), the Interstate Identification Index (III), and the NICS Index. A POC may check additional State records. A check may include contacting an agency that maintains a record that the FBI or POC cannot access directly. After a search, the checking agency responds with a notice to the licensee that the transfer may proceed, may not proceed, or is delayed pending further review of the applicant's record. Other notes: State forbids pawning a handgun = AL, IN, MA, MI, NJ (all firearms), NH, PA

About this dataset

Context

The dataset tabulates the Gun Barrel City population distribution across 18 age groups. It lists the population in each age group along with the percentage population relative of the total population for Gun Barrel City. The dataset can be utilized to understand the population distribution of Gun Barrel City by age. For example, using this dataset, we can identify the largest age group in Gun Barrel City.

Key observations

The largest age group in Gun Barrel City, TX was for the group of age 60 to 64 years years with a population of 612 (9.55%), according to the ACS 2019-2023 5-Year Estimates. At the same time, the smallest age group in Gun Barrel City, TX was the 85 years and over years with a population of 126 (1.97%). Source: U.S. Census Bureau American Community Survey (ACS) 2019-2023 5-Year Estimates

Content

When available, the data consists of estimates from the U.S. Census Bureau American Community Survey (ACS) 2019-2023 5-Year Estimates

Age groups:

• Under 5 years
• 5 to 9 years
• 10 to 14 years
• 15 to 19 years
• 20 to 24 years
• 25 to 29 years
• 30 to 34 years
• 35 to 39 years
• 40 to 44 years
• 45 to 49 years
• 50 to 54 years
• 55 to 59 years
• 60 to 64 years
• 65 to 69 years
• 70 to 74 years
• 75 to 79 years
• 80 to 84 years
• 85 years and over

Variables / Data Columns

• Age Group: This column displays the age group in consideration
• Population: The population for the specific age group in the Gun Barrel City is shown in this column.
• % of Total Population: This column displays the population of each age group as a proportion of Gun Barrel City total population. Please note that the sum of all percentages may not equal one due to rounding of values.

Good to know

Margin of Error

Data in the dataset are based on the estimates and are subject to sampling variability and thus a margin of error. Neilsberg Research recommends using caution when presening these estimates in your research.

Custom data

If you do need custom data for any of your research project, report or presentation, you can contact our research staff at research@neilsberg.com for a feasibility of a custom tabulation on a fee-for-service basis.

Inspiration

Neilsberg Research Team curates, analyze and publishes demographics and economic data from a variety of public and proprietary sources, each of which often includes multiple surveys and programs. The large majority of Neilsberg Research aggregated datasets and insights is made available for free download at https://www.neilsberg.com/research/.

Recommended for further research

This dataset is a part of the main dataset for Gun Barrel City Population by Age. You can refer the same here

THIS DATASET WAS LAST UPDATED AT 8:11 PM EASTERN ON SEPT. 30

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.

Weapons Sales in the United States increased to 13512 SIPRI TIV Million in 2024 from 11102 SIPRI TIV Million in 2023. United States Weapons Sales - values, historical data, forecasts and news - updated on October of 2025.

This dataset was compiled from the ATF 2007 report on firearms trace data. The numbers provided represent the top 15 source states of firearms for each state. The number and percentage of out of state guns are also calculated.

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

This dataset consists of gun violence within Jefferson county that may fall within LMPDs radar, including non-fatal shootings, homicides, as well as shot-spotter data. The mapping data points where there are victims have been obfuscated to maintain privacy, while still being accurate enough to be placed in its correct boundaries, particularly around, neighborhoods, ZIP Codes, Council districts, and police divisions. The data also excludes any victim information that could be used to identify any individual. this data is used to make the public aware of what is going on in their communities. The data consists of only criminal incidents, excluding any cases that are deemed non-criminal.Field NameField DescriptionCase numberPolice report number. For ShotSpotter detections, it is the ShotSpotter ID.DateTimeDate and time in which the original incident occurred. Time is rounded down.AddressAddress rounded down to the one hundred block of where the initial incident occured. Unless it is an intersection.NeighborhoodNeighborhood in which the original incident occurred.Council DistrictCouncil district in which the original incident occurred.LatitudeLatitude coordinate used to map the incidentLongitudeLongitude coordinate used to map the incidentZIP CodeZIP Code in which the original incident occurred.Crime Typea distinction between incidents, whether it is a non-fatal shooting, homicide, or a ShotSpotter detection.CauseUsed to differentiate on the cause of death for homicide victims.SexGender of the victim of the initial incident.RaceRace/Ethnicity of the victim in a given incident.Age GroupCategorized age groups used to anonymize victim information.Division NamePolice division or department where the initial incident occurred.Crime report data is provided for Louisville Metro Police Divisions only; crime data does not include smaller class cities, unless LMPD becomes involved in smaller agency incident.The data provided in this dataset is preliminary in nature and may have not been investigated by a detective at the time of download. The data is therefore subject to change after a complete investigation. This data represents only calls for police service where a police incident report was taken. Due to the variations in local laws and ordinances involving crimes across the nation, whether another agency utilizes Uniform Crime Report (UCR) or National Incident Based Reporting System (NIBRS) guidelines, and the results learned after an official investigation, comparisons should not be made between the statistics generated with this dataset to any other official police reports. Totals in the database may vary considerably from official totals following the investigation and final categorization of a crime. Therefore, the data should not be used for comparisons with Uniform Crime Report or other summary statistics.Contact:Ivan Benitez, Ph.D.Gun Violence Data FellowOffice for Safe and Healthy Neighborhoodsivan.benitez@louisvilleky.gov

Data tables relating to offences involving weapons as recorded by police and hospital episode statistics.

This dataset looks at age and juvenile offender status as a means of restricting the purchase and possession of firearms in the USA as of 12.31.2005. This data displays the minimum age you must be to purchase/possess a handgun or a long gun in every state in the USA. It also displays if a state restricts juvenile offenders from purchasing/possessing a firearm, handguns or long guns. Also provided in the data is the statute within the States legislation that states the firearm purchase/possession restriction. Handgun: A firearm that has a short stock and is designed to be held and fired by the use of a single hand, such as a pistol or revolver. Long gun: A firearm with a barrel extended to around 30 inches to improve accuracy and range, and commonly with a shoulder butt, designed to be fired with two hands, such as a rifle or shotgun. This data comes from Survey of State Procedures Related to Firearm Transfers, 2005. The Survey provides an overview of the firearm check procedures in each State and State interaction with the National Instant Criminal Background Check System (NICS) operated by the FBI. The report summarizes issues about State procedures, including persons prohibited from purchasing firearms, restoration of rights of purchase to prohibited persons, permits, prohibited firearms, waiting periods, fees, and appeals. Supplemental tables contain data on 2005 applications to purchase firearms and rejections, as well as tabular presentations of State-by-State responses. This is one of a series of reports published from the BJS Firearm Inquiry Statistics (FIST) project, managed under the BJS National Criminal History Improvement Program (NCHIP). This is a web only document.

The Office of Gun Violence Prevention (OGVP) shares real-time gun violence data to increase government transparency, improve the public's awareness, and support community-based gun violence prevention and reduction partners. All District crime data is available through Crime Cards. The dashboards below focus on gun violence only. The data in these dashboards is updated daily at 7:40AM with the incidents from the day before. View data covering 7-Day Look-back of Gun Violence and Year-to-date Gun Violence.All statistics presented here are based on preliminary DC criminal code offense definitions. The data do not represent official statistics submitted to the FBI under the Uniform Crime Reporting program (UCR) or National Incident Based Reporting System (NIBRS). All preliminary offenses are coded based on DC criminal code and not the FBI offense classifications. Please understand that any comparisons between MPD preliminary data as published on this website and the official crime statistics published by the FBI under the Uniform Crime Reporting Program (UCR) are inaccurate and misleading. The MPD does not guarantee (either expressed or implied) the accuracy, completeness, timeliness, or correct sequencing of the information. The MPD will not be responsible for any error or omission, or for the use of, or the results obtained from the use of this information. Read complete data notes at buildingblocks.dc.gov/data.

About this dataset

Context

The dataset tabulates the Gun Plain township population distribution across 18 age groups. It lists the population in each age group along with the percentage population relative of the total population for Gun Plain township. The dataset can be utilized to understand the population distribution of Gun Plain township by age. For example, using this dataset, we can identify the largest age group in Gun Plain township.

Key observations

The largest age group in Gun Plain Township, Michigan was for the group of age 50 to 54 years years with a population of 621 (10.09%), according to the ACS 2019-2023 5-Year Estimates. At the same time, the smallest age group in Gun Plain Township, Michigan was the 85 years and over years with a population of 34 (0.55%). Source: U.S. Census Bureau American Community Survey (ACS) 2019-2023 5-Year Estimates

Content

When available, the data consists of estimates from the U.S. Census Bureau American Community Survey (ACS) 2019-2023 5-Year Estimates

Age groups:

• Under 5 years
• 5 to 9 years
• 10 to 14 years
• 15 to 19 years
• 20 to 24 years
• 25 to 29 years
• 30 to 34 years
• 35 to 39 years
• 40 to 44 years
• 45 to 49 years
• 50 to 54 years
• 55 to 59 years
• 60 to 64 years
• 65 to 69 years
• 70 to 74 years
• 75 to 79 years
• 80 to 84 years
• 85 years and over

Variables / Data Columns

• Age Group: This column displays the age group in consideration
• Population: The population for the specific age group in the Gun Plain township is shown in this column.
• % of Total Population: This column displays the population of each age group as a proportion of Gun Plain township total population. Please note that the sum of all percentages may not equal one due to rounding of values.

Good to know

Margin of Error

Data in the dataset are based on the estimates and are subject to sampling variability and thus a margin of error. Neilsberg Research recommends using caution when presening these estimates in your research.

Custom data

If you do need custom data for any of your research project, report or presentation, you can contact our research staff at research@neilsberg.com for a feasibility of a custom tabulation on a fee-for-service basis.

Inspiration

Neilsberg Research Team curates, analyze and publishes demographics and economic data from a variety of public and proprietary sources, each of which often includes multiple surveys and programs. The large majority of Neilsberg Research aggregated datasets and insights is made available for free download at https://www.neilsberg.com/research/.

Recommended for further research

This dataset is a part of the main dataset for Gun Plain township Population by Age. You can refer the same here

This dataset is part of the UCR Archive maintained by University of Southampton researchers. Please cite a relevant or the latest full archive release if you use the datasets. See http://www.timeseriesclassification.com/.

This dataset is a remake of the famous GunPoint dataset released in 2003. We strive to mimic in every aspect the recording of the original GunPoint. The actors include one male and one female. They are the same actors who created the original GunPoint. We record two scenarios, Gun and Point (also known as Gun and NoGun). In each scenario, the actors aim at a eye-level target. The difference between Gun and Point is that for the Gun scenario, the actors hold a gun, and in the Point scenario, the actors point with just their fingers. A complete Gun action involves the actor moves hand from an initial rest position, points the gun at target, puts gun back to waist holster and then brings free hand to the initial rest position. Each complete action conforms to a five-second cycle. With 30fps, this translates into 150 frames per action. We extract the centroid of the hand from each frame and use its x-axis coordinate to form a time series. We refer to the old GunPoint as GunPoint 2003 and the new GunPoint as Gunpoint 2018. We merged GunPoint 2003 and GunPoint 2018 to make three datasets. Let us denote: - G: Gun - P: Point - M: Male - F: Female - 03: The year 2003 - 18: The year 2018 ## GunPointAgeSpan The task is to classify Gun and Point. There are 4 flavors of each class. - Class 1: Gun (FG03, MG03, FG18, MG18) - Class 2: Point (FP03, MP03, FP18, MP18) ## GunPointMaleVersusFemale The task is to classify Male and Female. There are 4 flavors of each class. - Class 1: Female (FG03, FP03, FG18, FP18) - Class 2: Male (MG03, MP03, MG18, MP18) ## GunPointOldVersusYoung The task is to classify the older and younger version of the actors. There are 4 flavors of each class. - Class 1: Young (FG03, MG03, FP03, MP03) - Class 2: Old (FG18, MG18, FP18, MP18) There is nothing to infer from the order of examples in the train and test set. Data created by Ann Ratanamahatana and Eamonn Keogh. Data edited by Hoang Anh Dau.

Donator: A. Ratanamahatana, E. Keogh

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.

Roboflow Dataset Page

https://universe.roboflow.com/ashish-cuamw/test-y7rj3

  Citation

@misc{ test-y7rj3_dataset, title = { test Dataset }, type = { Open Source Dataset }, author = { ashish }, howpublished = { \url{ https://universe.roboflow.com/ashish-cuamw/test-y7rj3 } }, url = { https://universe.roboflow.com/ashish-cuamw/test-y7rj3 }, journal = { Roboflow Universe }, publisher = { Roboflow }, year = { 2022 }, month = { oct }, note… See the full description on the dataset page: https://huggingface.co/datasets/fcakyon/gun-object-detection.

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.