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.

As of August 2025, California had the most mass shootings in the United States, with 26 total shootings since 1982. The source defines a mass shooting as a shooting where three or more people were killed. Recently, a mass shooting occurred in the state of Maine on October 26, 2023, during which one of the highest number of fatalities from a mass shooting was recorded after Robert Card opened fire in a bowling alley and a bar, killing 18 and injuring 13 others. Firearms in the U.S. Mass shootings in the United States are disturbingly common. In comparison with other Western countries, there are significantly more shootings in the U.S., which some theorize is due to the relatively lax gun control laws. Gun control laws in the U.S. are dependent on the state, and the right to own a firearm is enshrined in the United States Constitution. Mass shootings The worst mass shooting in the U.S. was the Las Vegas Strip massacre in 2017, which resulted in 58 deaths and 546 injuries. 13 of the worst mass shootings in the United States have occurred since 2015 and the vast majority of these incidents in the U.S. have been carried out by shooters who are White and male.

Number and percentage of homicide victims, by type of firearm used to commit the homicide (total firearms; handgun; rifle or shotgun; fully automatic firearm; sawed-off rifle or shotgun; firearm-like weapons; other firearms, type unknown), Canada, 1974 to 2018.

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.

Handguns are by far the most common murder weapon used in the United States, accounting for 7,159 homicides in 2023. This is followed by firearms of an unstated type, with 5,295 cases in that year. Why do murders happen in the U.S.? While most of the time the circumstances of murders in the U.S. remain unknown, homicides due to narcotics come in as the second most common circumstance – making them more common than, for example, gang killings. Despite these gruesome facts, the violent crime rate has fallen significantly since 1990, and the United States is much safer than it was in the 1980s and 1990s. Knife crime vs disease: Leading causes of death The death rate in the U.S. had hovered around the same level since 1990 until there was a large increase due to the COVID-19 pandemic in recent years. Heart disease, cancer, and accidents were the three leading causes of death in the country in 2022. The rate of death from heart disease is significantly higher than the homicide rate in the United States, at 167.2 deaths per 100,000 population compared to a 5.7 homicides per 100,000. Given just 1,562 murders were caused by knife crime, it is fair to say that heart disease is a far bigger killer in the U.S.

As of August 11, there were four mass shootings in the United States in 2025. This is compared to one mass shooting in 1982, one in 2000, and 12 mass shootings in 2022 and 2023. School shootings The United States sees the most school shootings in the world. Some motivations for school shootings included depression, seeking revenge, and bullying. As a result of the large amount of school shootings, gun control has become a central topic in U.S. politics. This widespread problem happens across the United States; however California saw the highest number of K-12 school shootings in the United States since 1970. However, the deadliest school shooting (as of October 2023) was the Virginia Tech massacre in 2007. This tragedy left 33 dead and 23 injured. Mass shooting issues Mass shootings happen when there are several injuries or deaths from a firearm-related violence. Throughout the last century, mass shootings have become an epidemic in the United States. However, despite the increase in mass shootings and number of casualties, the U.S. government has done little to prevent future shootings from happening. As a result of the lack of cooperation in politics, mass shootings have become an important issue for Generation Z living in the United States. Furthermore, having the right to bear arms is a popular belief in the U.S. and the percentage of households in the United States owning at least one firearm has remained somewhat steady since 1972.

In 2023, there were ****** fatalities caused by injuries related to firearms in the United States, a slight decrease from the previous year. In 2021, there were ****** firearm deaths, the highest number of gun deaths ever recorded in the country. However, this figure has remained relatively high over the past 25 years, with ****** firearm deaths in 1990 and a slight dip in fatalities between 1999 and 2002. Firearms in the United States The right to own firearms in the United States is enshrined in the 2nd Amendment of the U.S. Constitution, and while this right may be seen as quintessentially American, the relationship between Americans and their firearms has become fraught in the last few years. The proliferation of mass shootings in the U.S. has brought the topic of gun control into the national spotlight, with support for banning assault-style weapons a particularly divisive issue among Americans. Gun control With a little less than **** of all Americans owning at least one firearm and the highest rate of civilian gun ownership in the world, it is easy to see how the idea of gun control is a political minefield in the U.S. However, public opinion has begun to shift over the past ten years, and a majority of Americans report that laws governing the sale of firearms should be stricter than they are now.

Number of homicide victims, by method used to commit the homicide (total methods used; shooting; stabbing; beating; strangulation; fire (burns or suffocation); other methods used; methods used unknown), Canada, 1974 to 2024.

100 of the mass shootings in the United States between 1982 and September 2024 involved weapons which were obtained legally; a clear majority. Only 16 incidents involved guns that were obtained illegally. Legally owned firearms in the U.S. Within the United States, one must be at least 18 years old in order to purchase shotguns, rifles, and ammunition, and at least 21 years old to purchase all other firearms. Some people may be restricted from owning firearms, such as individuals who have been dishonorably discharged from the military or tourists. Guns must be sold through licensed dealers, and purchasers must undergo a background check. However, the much-discussed “gun show loophole” allows people to purchase firearms from a flea market, gun show, online, or from a personal collector without a background check. The national firearm conversation The right to own a gun in the United States is protected by the 2nd Amendment of the Constitution. While changing a part of the Bill of Rights (the first 10 amendments to the Constitution) would be extremely difficult, the issue of gun rights has become a highly controversial, and highly partisan, topic in the national conversation. For example, a majority of Republicans believe that if legal gun ownership is controlled, that there will not be a difference in the number of mass shootings. In contrast, most Democrats believe the number will decrease.

In 2023, 13,529 recorded murders in the United States were committed by firearm. This is a decrease from the previous year, when 12,244 homicides were committed with a firearm in the country. However, figures may not accurately reflect the total number of homicides, as not all law enforcement agencies in the U.S. submitted homicide data.

The Shootings dashboard contains information on shooting incidents where a victim was struck by a bullet, either fatally or non-fatally; that occurred in the City of Boston and fall under Boston Police Department jurisdiction. The dashboard does not contain records for self-inflicted gunshot wounds or shootings determined to be justifiable. Information on the incident, and the demographics of victims are included. This information is updated based on analysis conducted by the Boston Regional Intelligence Center under the Boston Police Department Bureau of Intelligence and Analysis. The data is for 2015 forward, with a 7 day rolling delay to allow for analysis and data entry to occur.

Number and rate (per 100,000 population) of homicide victims, Canada and Census Metropolitan Areas, 1981 to 2024.

Knives or other sharp objects were involved in ** percent of homicides in England and Wales in 2023/24, the most of any method of killing. Homicides which involved hitting or kicking without a weapon made up **** percent of homicides, while shootings were identified as the method in *** percent of homicides. Overall, there were *** homicides in this reporting year, which was slightly lower than in the previous year, when there were ***, but noticeably higher than in 2014/15, when there were ***. Firearm homicides rare in England and Wales In 2023/24, there were *** knife homicides in England and Wales, compared with *** in 2021/22, which was the highest figure recently. By comparison, homicides which involved the use of a firearm were far less common, with just ** in the 2023/24 reporting year. Due to strict gun laws and low levels of ownership, the UK contrasts starkly with the United States, which has struggled with high levels of gun violence. Although some specialist police officers in England and Wales are licensed to carry firearms, the majority of police officers are unarmed. In 2023/24, for example, there were just ***** armed police, out of around ******* police officers. Overall knife crime on the rise Like many other types of crime, knife crime offences in the ***** started to decline at the start of the decade before creeping up again from 2014 onwards, reaching almost ****** in 2019/20. In London, where much of the media’s attention on knife crime is focused, there were ****** knife crime offences alone in 2019/20. Although this fell during subsequent reporting years, which were influenced by COVID-19 restrictions, it remains to be seen if the trend will continue. In 2023/24, the number of knife offences in the capital was higher than in any other year since 2019/20.

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.

Handguns are the most common weapon type used in mass shootings in the United States, with a total of 167 different handguns being used in 117 incidents between 1982 and September 2024. These figures are calculated from a total of 151 reported cases over this period, meaning handguns are involved in about 78 percent of mass shootings. The involvement of semi-automatic rifles in mass shootings Owing to their use in several high-profile mass shootings, there has been much public discussion over the suitability or necessity of assault weapons for the purpose of self-defense. While any definition of assault weapon is contentious, semi-automatic rifles are generally the main focus of debates around this issue. Since 1982, there has been a known total 65 mass shootings involving rifles, mostly semi-automatics. This figure is underreported, however, as it excludes the multiple semi-automatic (and fully automatic) rifles used in the 2017 Las Vegas Strip massacre – the worst mass shooting in U.S. history, killing 58 and wounding 546. In fact, semi-automatic rifles were featured in four of the five deadliest mass shootings, being used in the Orlando nightclub massacre, Sandy Hook Elementary massacre and Texas First Baptist Church massacre. Mass shootings and gun control Despite evidence of strict gun control measures reducing the frequency and severity of mass shootings in countries like Australia, citizens in the United States remain deeply divided over the issue. According to a survey about the expected impact of gun laws on the number of mass shootings, a slim majority of Americans believe that gun control measures will have little-to-no effect. Most likely, this opinion is influenced by an underlying commitment among many in the U.S. to the greater importance of protecting gun ownership rights than limiting access to firearms. This sits in sharp contrast to many other developed countries. For example, most Canadians support a ban on civilian owned firearms.

For most of the last 35 years, the number of police officers who die on the job in the U.S. declined, but one grim statistic held steady: The most common cause of death was gun homicide. Those numbers grew significantly on Thursday night when five police officers were shot and killed at a demonstration in Dallas that was protesting recent killings by police officers in other states. President Obama called it “a vicious, calculated and despicable attack on law enforcement.” Per officer, policing had become even safer in recent years than the overall death counts suggest, which makes the Dallas shooting that much more of a singular, horrific massacre. That’s because the decline in the number of deaths by police officers in the line of duty has occurred as the number of officers has risen. The number of full-time, sworn local police officers increased by 35 percent from 1987 to 2013, according to the Bureau of Justice Statistics. During that same period, the number of officers killed declined by 34 percent. 1 And a growing share of officer deaths are happening in accidental or deliberate car collisions.

Context

1 in 4 mass shooting victims were children and teens. In the years between 2009 and 2020, the horrific scenes of mass shootings have haunted the nation’s collective conscience.US states with weaker gun laws and higher gun ownership rates have higher rates of mass shootings. Mass shooting is defined as any incident in which four or more people are shot and killed, excluding the shooter. The number of mass shootings that plague this country is far too high, and the counts are just a small fraction of the lives left forever changed after the tragedy of a mass shooting. So here is the data for list of mass shootings in United States from 2018 - 2022.

Content

This dataset has five csv files of years 2018 - 2022. Each data contains following attributes - Date : The date on which the mass shooting incident happened - State : The state where the incident took place - Dead : total number of people died in mass shooting - Injured: total number of people who got injured in mass shooting- - Total : total of dead and injured people - Description : description/short report of the incident which may include information like gender/place etc. Data for 2022 Mass shootings will be updated every 15 days!

Acknowledgements

This data was scraped from https://en.wikipedia.org/wiki/List_of_mass_shootings_in_the_United_States using BeautifulSoup.

Image banner by Wall Street Journal

Inspiration

• EDA and Viz.
• Which state has highest number of mass shootings
• Contextual analysis of the description column
• Trend of mass shooting in past years
• Number of people killed/injured on an average in a month.

Check out my other works

• Datasets
• Notebooks

Victims of gang-related homicides (total number of homicide victims; number of homicide victims - unknown gang-relation; number of homicide victims - known gang relation; number of gang-related homicide victims; percentage of gang-related homicide victims; rate (per 100,000 population) of gang-related homicide victims), Canada and regions, 1999 to 2024.

Context

There's currently a lack of large and easily-accessible amounts of detailed data on gun violence.

Content

This project aims to change that; we make a record of more than 260k gun violence incidents, with detailed information about each incident, available in CSV format. We hope that this will make it easier for data scientists and statisticians to study gun violence and make informed predictions about future trends.

The CSV file contains data for all recorded gun violence incidents in the US between January 2013 and March 2018, inclusive.

Acknowledgements

Where did you get the data?

The data was downloaded from gunviolencearchive.org. From the organization's description:

Gun Violence Archive (GVA) is a not for profit corporation formed in 2013 to provide free online public access to accurate information about gun-related violence in the United States. GVA will collect and check for accuracy, comprehensive information about gun-related violence in the U.S. and then post and disseminate it online.

How did you get the data?

Because GVA limits the number of incidents that are returned from a single query, and because the website's "Export to CSV" functionality was missing crucial fields, it was necessary to obtain this dataset using web scraping techniques.

Stage 1: For each date between 1/1/2013 and 3/31/2018, a Python script queried all incidents that happened at that particular date, then scraped the data and wrote it to a CSV file. Each month got its own CSV file, with the exception of 2013, since not many incidents were recorded from then.

Stage 2: Each entry was augmented with additional data not directly viewable from the query results page, such as participant information, geolocation data, etc.

Stage 3: The entries were sorted in order of increasing date, then merged into a single CSV file.

Inspiration

I believe there are plenty of ways this dataset can be put to good use. If you have an interesting idea or feel like messing around with the data, then go for it.

I was originally inspired to compile it in the wake of the Parkland shooting and the mass media coverage that followed. Reports like this and this showed that Nikolas Cruz had exhibited plenty of warning signs on social media before the shooting; what if we could build a machine learning system that preemptively detected such signs?

The deadliest school shooting in the United States as of August 11, 2025, was the Virginia Tech massacre, with 32 fatalities and 23 injuries. The next deadliest school shooting (based on fatalities) was the Sandy Hook Elementary massacre in Newtown, Connecticut, with 27 fatalities. School shootings in the U.S. Mass shootings in the United States have become a disturbingly common occurrence, and sadly, so have school shootings. The Columbine school shooting is perhaps the most famous in the country’s history, and since 1999 (when the shooting occurred), the number of school shootings has only increased. Many measures have been used to try to prevent school shootings, including security guards and metal detectors being deployed in schools, and even the suggestion that teachers be allowed to carry guns in schools. Gun control Gun control in the United States is a sticky issue, since gun ownership is enshrined in the Constitution. Some advocate for stricter gun control laws to try to prevent future mass shootings, while others say that this is unconstitutional. Gun ownership rates in the U.S. are high, with the share of American households owning at least one firearm remaining relatively steady since 1972.