In undertaking this data collection, the principal investigators sought to determine (1) whether police enforcement against drug crimes, specifically heroin crimes, had any influence on the rates of nondrug crimes, and (2) what effect intensive law enforcement programs against drug dealers had on residents where those programs were operating. To achieve these objectives, data on crime rates for seven successive years were collected from police records of 30 cities in Massachusetts. Data were collected for the following offenses: murder, rape, robbery, assault, larceny, and automobile theft. The investigators also interviewed a sample of residents from 3 of those 30 cities. Residents were queried about their opinions of the most serious problem facing people today, their degree of concern about being victims of crime, and their opinions of the effectiveness of law enforcement agencies in handling drug problems.

Crime incident reports are provided by Boston Police Department (BPD) to document the initial details surrounding an incident to which BPD officers respond. This is a dataset containing records from the new crime incident report system, which includes a reduced set of fields focused on capturing the type of incident as well as when and where it occurred. Records in the new system begin in June of 2015.

The Analyze Boston Data Exports posted now are the updated incident data from the Mark43 RMS Database which launched in September of 2019 and is complete through present with the exclusion of data that falls under MGL ch.41 s.98f. The 2019 data that was originally posted contained combined exports from the Intergraph RMS and the Mark43 RMS during 2019 but the Extract/Transfer/Load process was not updated during the transition.

This dataset contains crime reports from the City of Somerville Police Department's records management system from 2017 to present. Each data point represents an incident, which may involve multiple offenses (the most severe offense is provided here).

Incidents deemed sensitive by enforcement agencies are included in the data set but are stripped of time or location information to protect the privacy of victims. For these incidents, only the year of the offense is provided.

This data set is refreshed daily with data appearing with a one-month delay (for example, crime reports from 1/1 will appear on 2/1). If a daily update does not refresh, please email data@somervillema.gov.

In 2023, the District of Columbia had the highest reported violent crime rate in the United States, with 1,150.9 violent crimes per 100,000 of the population. Maine had the lowest reported violent crime rate, with 102.5 offenses per 100,000 of the population. Life in the District The District of Columbia has seen a fluctuating population over the past few decades. Its population decreased throughout the 1990s, when its crime rate was at its peak, but has been steadily recovering since then. While unemployment in the District has also been falling, it still has had a high poverty rate in recent years. The gentrification of certain areas within Washington, D.C. over the past few years has made the contrast between rich and poor even greater and is also pushing crime out into the Maryland and Virginia suburbs around the District. Law enforcement in the U.S. Crime in the U.S. is trending downwards compared to years past, despite Americans feeling that crime is a problem in their country. In addition, the number of full-time law enforcement officers in the U.S. has increased recently, who, in keeping with the lower rate of crime, have also made fewer arrests than in years past.

The effects of a deliberate strategy to bolster organizational change in order to achieve the goals of the Comprehensive Gang Model (CGM) were tested in this study. The CGM goals of increasing community capacity to address gang and youth violence and reducing gang and youth violence were examined. A quasi-experimental design was used wherein two Massachusetts cities received a relational coordination intervention to boost organizational change and two similar Massachusetts cities were used as comparisons. Surveys, observational notes, and crime data assessed outcomes of interest. The intervention was carried out from March 2016 through August 2017. Survey and observational data were gathered during that time. Crime data from January 2014 through December 2018 was utilized to examine outcomes.

THIS DATASET WAS LAST UPDATED AT 8:10 PM EASTERN ON MARCH 24

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.

In recent years, gun violence in the United States has become an alarmingly common occurrence. From 2016, there has been over 10,000 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 29.4 percent, followed by Louisiana, at 28.1 percent. In comparison, Massachusetts had a gun violence rate of 3.7 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 80 percent of Democrats believing that it was more important to limit gun ownership while 74 percent of Republicans felt that it was more important to protect the right of Americans to own guns.

In 2023, 1,970 hate crime offenses were reported in California, the most out of any state. New Jersey, New York, Washington, and Massachusetts rounded out the top five states for hate crime offenses in that year.

As of September 2024, 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.

California reported the largest number of homicides to the FBI in 2023, at 1,929 for the year. Texas recorded the second-highest number of murders, with 1,845 for the year. Homicide victim demographics There were a total of 19,252 reported homicide cases in the U.S. in 2023. When looking at murder victims by gender and ethnicity, the vast majority were male, while just over half of the victims were Black or African American. In addition, homicide victims in the United States were found most likely to be between the ages of 20 and 34 years old, with the majority of victims aged between 17 to 54 years old. Are murders up? In short, no – since the 1990s the number of murders in the U.S. has decreased significantly. In 1990, the murder rate per 100,000 people stood at 9.4, and stood at 5.7 in 2023. It should be noted though that the number of homicides increased slightly from 2014 to 2017, although figures declined again in 2018 and 2019, before ticking up once more in 2020 and 2021. Despite this decline, when viewed in international comparison, the U.S. murder rate is still notably high. For example, the Canadian homicide rate stood at 1.94 in 2023, while the homicide rate in England and Wales was even lower.

On October 1, 2017, the highest number of fatalities from a mass shooting in the United States was recorded when Stephen Paddock attacked a crowd of concert-goers on the Las Vegas strip, killing 58 and injuring 546 others, then taking his own life before authorities could apprehend him. Most recently, one of the worst mass shootings in the U.S. occurred in Maine on October 26, 2023, when Robert Card, an Army reservist and firearms instructor, opened fire in a bowling alley and a bar, killing 18 and injuring 13 others. Card then became the focus of a two-day-long manhunt, until he was found dead from a self-inflicted gunshot.

Lynching in the United States is estimated to have claimed over 4.7 thousand lives between 1882 and 1968, and just under 3.5 thousand of these victims were black. Today, lynching is more commonly associated with racial oppression, particularly in the south, however, in early years, victims were more commonly white (specifically Mexican), and lynchings were more frequent in western territories and along the southern border. It was only after Reconstruction's end where the lynching of black people became more prevalent, and was arguably the most violent tool of oppression used by white supremacists. Nationwide, the share of the population who was black fluctuated between 10 and 13 percent in the years shown here, however the share of lynching victims who were black was almost 73 percent. North-south divide Of the 4.7 thousand victims of lynching between 1882 and 1968, over 3.5 thousand of these were killed in former-Confederate states. Of the fourteen states where the highest number of lynching victims were killed, eleven were former-Confederate states, and all saw the deaths of at least one hundred people due to lynching. Mississippi was the state where most people were lynched in these years, with an estimated 581 victims, 93 percent of whom were black. Georgia saw the second most lynchings, with 531 in total, and the share of black victims was also 93 percent. Compared to the nationwide average of 73 percent, the share of black victims in former-Confederate states was 86 percent. Texas was the only former-Confederate state where this share (71 percent) was below the national average, due to the large number of Mexicans who were lynched there. Outside of the south Of the non-Confederate state with the highest number of lynching victims, most either bordered the former-Confederate states, or were to the west. Generally speaking, the share of white victims in these states was often higher than in the south, meaning that the majority took place in the earlier years represented here; something often attributed to the lack of an established judiciary system in rural regions, and the demand for a speedy resolution. However, there are many reports of black people being lynched in the former border states in the early-20th century, as they made their way northward during the Great Migration. Between 1882 and 1968, lynchings were rare in the Northeast, although Connecticut, Massachusetts, New Hampshire and Rhode Island were the only states** without any recorded lynchings in these years.

Alaska saw the highest rape rate in the United States in 2023, with 118.4 rapes per 100,000 inhabitants. The lowest rate was found in New Jersey, with 17.9 rapes per 100,000 inhabitants. Sexual assault in Alaska Fighting sexual assault in Alaska is particularly difficult due to small, isolated, close-knit communities who can be wary of airing their dirty laundry to outsiders, as well as a low number of law enforcement employees in the state. In addition, Alaska’s low population is spread out over a large land area, meaning that in the event of an assault being reported to police, it can take law enforcement hours, or even days, to reach the most isolated communities. The victims of sexual assault There tends to be more reported female victims of sexual assault than male victims. However, since sexual assault is typically an underreported crime, especially among males, these figures could be, and probably are, much higher. In addition, many victims of sexual offenses tend to be young, although sexual assault can occur at any age.