In 2023, 76.37 percent of homicides were committed by firearm in the United States, compared to 85.7 percent in 2021. This figure has been increasing since 2014, when 63.6 percent of homicides were committed by firearm. Firearms in the United States Firearms in the United States have become a large part of American culture. The Second Amendment of the Constitution protects the right to keep and bear arms. This amendment has been cited as a reason why gun control laws should not become stricter. However, many Americans are in favor of stricter gun control laws due to the increase of shootings in the country. Handguns were the most frequently used weapon used on murder victims in 2020, and overall, the United States was the country with the highest rate of civilian-owned firearms. Who owns firearms? Firearms are more popular in certain parts of the United States than others. Texas was the state with the highest number of registered weapons in 2021, with Florida, Virginia, California, and Pennsylvania rounding out the top five. Firearm laws vary from state to state, which means it is easier to obtain a firearm in some states than in others. Gun owners in the United States are typically white, and men are more likely to personally own a gun than women.

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 2023.

In 2023, about 1,459 homicides were committed with the use of firearms in Texas. A further 1,334 homicides were committed with a firearm in California in that year. A ranking of the total number of murders by U.S. state can be found here.

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 2023.

For the first time ever, firearms and motor vehicles are killing Americans at an identical rate, according to an analysis of Centers for Disease Control data by the Violence Prevention Project at University of California, Davis.The convergence of the rates of these causes of death is primarily due to a dramatic drop in the rate of motor vehicle fatalities since the early 1970s. The current rate of gun deaths is higher than the 1950s and 1960s, but lower than the three decades that followed.

Number and rate (per 100,000 population) of homicide victims, Canada and Census Metropolitan Areas, 1981 to 2023.

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.

Number, rate and percentage changes in rates of homicide victims, Canada, provinces and territories, 1961 to 2023.

California led the way in gun safety in the United States as of January 2025, with a composite score of 90.5 based on the presence of 50 key gun safety policies. Massachusetts followed, with a score of 86.5, while Illinois rounded out the top three with a score of 85.5. Illinois joins the no-assault weapons club In 2023, Illinois came in seventh place for gun law strength; by 2024, this ranking rose to third, signifying that the state holds some of the strongest gun safety laws nationwide. However, this swift rise up the ranks also suggests that Illinois is still taking action against gun violence, particularly after seven people were killed and dozens were injured in a mass shooting in Chicago during a Fourth of July parade in 2022. In recent years, Illinois has consistently improved state legislation on gun safety and has enacted multiple measures to prevent further harm from firearms, including a statewide ban on assault weapons which was approved in January 2023. The Midwestern state joined eight other states, as well as Washington, D.C., which prohibits military-style weapons. Permissive open carry states dominate the bottom of the class Receiving less than five points each, Arkansas, Mississippi, and Idaho represent the lowest composite score for gun law strength nationwide. Arkansas, Mississippi, and Idaho are among the 25 U.S. states that do not require any permit to carry concealed guns in public, and are permissive open carry states as well. Moreover, these states do not require a permit or a background check to purchase a handgun and also neglect to necessitate any firearm safety training before making the purchase. Such gun safety laws are considered crucial to ensure that firearms are handled properly and do not cause anyone harm. However, it is also important to note that countries with strong safety measures may still experience high rates of gun violence due to illegal gun trafficking. As a result, taking legal action may not fully address all gun-related violence in the area, especially if there remains an illicit way for people to obtain a gun without restriction.

As of September 4, there were two mass shootings in the United States in 2024. 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.

Number, percentage and rate (per 100,000 population) of homicide victims, by racialized identity group (total, by racialized identity group; racialized identity group; South Asian; Chinese; Black; Filipino; Arab; Latin American; Southeast Asian; West Asian; Korean; Japanese; other racialized identity group; multiple racialized identity; racialized identity, but racialized identity group is unknown; rest of the population; unknown racialized identity group), gender (all genders; male; female; gender unknown) and region (Canada; Atlantic region; Quebec; Ontario; Prairies region; British Columbia; territories), 2019 to 2023.

In 2023, an estimated 1,21,467 violent crimes occurred in the United States. This is a decrease from the year before, when 1,256,671 violent crimes were reported. Violent crime in the United States The Federal Bureau of Investigation reported that violent crime fell nationwide in the period from 1990 to 2023. Violent crime was at a height of 1.93 million crimes in 1992, but has since reached a low of 1.15 million violent crimes in 2014. When conducting crime reporting, the FBI’s Uniform Crime Reporting Program considered murder, nonnegligent manslaughter, forcible rape, robbery and aggravated assault to be violent crimes, because they are offenses which involve force or threat of violence. In 2023, there were 19,252 reported murder and nonnegligent manslaughter cases in the United States. California ranked first on a list of U.S. states by number of murders, followed by Texas, and Florida.The greatest number of murders were committed by murderers of unknown relationship to their victim. “Girlfriend” was the fourth most common relationship of victim to offender in 2023, with a reported 568 partners murdering their girlfriends that year, while the sixth most common was “wife.” In addition, seven people were murdered by their employees and 12 people were murdered by their employers. The most used murder weapon in 2023 was the handgun, which was used in 7,1 murders that year. According to the FBI, firearms (of all types) were used in more than half of the nation’s murders. The total number of firearms manufactured in the U.S. annually has reached over 13 million units.

As of July 14, 2025, there have been a total of 277 school shootings in California since 1966, the most out of any state. Texas had the second highest number of school shootings within this time period, with 237 shootings. The source defines a school shooting as every time a gun is brandished, fired, or a bullet hits school property for any reason, regardless of the number of victims (including zero), time, day or the week, or reason, including gang shootings, domestic violence, shootings at sports games and after hours school events, suicides, fights that escalate into shootings, and accidents.

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.

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.

This dissertation studies the effectiveness of various policies focusing on examining experimental and nonexperimental data using various methodologies. The first chapter presents a novel dataset of the universe of municipal gun ordinances between 2008 and 2019 to estimate the effects of gun ordinances on firearm fatalities. To do so, I isolate plausibly exogenous variation in the passage of municipal firearm ordinances that result from county level weather conditions on the day of the National School Walkout. I find no discernible effect of ordinances on firearm deaths at the county level. These estimates are precisely zero, and I can rule out any effects larger than a 1% change from the mean number of firearm deaths. In further analyses of effects by victim subgroups defined by race, education, and age, I again do not detect any significant impact of ordinances on deaths. The first stage provides evidence that increased turnout for the 2018 National School Walkout led to more firearm ordinances being passed. Counties in states with punitive firearm preemption laws are much less likely to pass firearm ordinances.

The second chapter conducts a randomized controlled trial of one such program. Participants randomly assigned to intensive, holistic, wrap-around services have 10 percentage points higher employment rates after one year compared with a control group offered only help with an immediate need (p=0.03). Most of this effect appears to persist after programming ends (p=0.13). However, we find limited evidence that intensive, holistic services affect areas beyond employment, even when other areas of life are participants' primary goals. We find some evidence that the program works by increasing hopefulness and agency among participants, which may be more useful in supporting labor force participation than in meeting other goals.

The third chapter studies California’s 2017 minimum wage law, which implemented a higher wage floor for firms with at least 26 employees. Using establishment-year data from the Longitudinal Business Database, we estimate the law’s effect on firm size. Applying a standard TWFE difference-in-differences approach, we find that the policy reduced the likelihood that California firms have just over 26 employees. The statistical significance of the estimates is sensitive to the inclusion of county-level controls interacted with year effects. We present suggestive evidence that the law disincentivizes firms from increasing employment.

Despite the diversity of topics, each chapter centers on evaluating how policy interventions shape economic and social outcomes. These papers are unified by their focus on real-world policies and programs—whether enacted by governments or nonprofit organizations. Across chapters, the aim is to understand how institutions can influence behaviors in ways that promote—or fail to promote—desired outcomes.

The policy questions addressed span different domains: gun violence, labor markets, and social services. They also vary across levels of government and institutional actors—from municipal and state governments to community-based nonprofits. Yet they are united by the central concern of whether and how interventions succeed. Together, these findings highlight where policy can be a powerful tool—and where it may fall short—offering evidence to guide smarter policy design.

Police-reported organized crime, by most serious violation (homicide and attempted murder, assault, sexual violations, kidnapping and hostage taking, human trafficking, robbery and theft, firearm and weapons violations, extortion and criminal harassment, arson, forgery and fraud, child pornography, criminal organization involvement, probation and court violations, drug possession and trafficking, and other violations), Canada (selected police services), 2016 to 2023.

In 2023, law enforcement officers committed 303 justifiable homicides in the United States. A justifiable homicide is defined as the killing of a felon during the commission of a felony. What is homicide? Homicide occurs when one person kills another; however it is not exactly the same as murder. It may or may not be considered criminal. Legal examples include a person killing an intruder in their home or capital punishment. There are different types of homicide, which includes murder and manslaughter. Homicide trends in the United States As of 2023, California had the highest number of homicides, followed by Texas, Florida, Pennsylvania, and North Carolina. That same year, murders with one victim and one offender were the most common in the United States. Overall, the United States has had a much higher rate of homicide in the past years when compared to their neighbor, Canada.

In 2023, around 3,640.56 violent crimes per 100,000 residents were reported in Oakland, California. This made Oakland the most dangerous city in the United States in that year. Four categories of violent crimes were used: murder and non-negligent manslaughter; forcible rape; robbery; and aggravated assault. Only cities with a population of at least 200,000 were considered.

The District of Columbia had the highest robbery rate in the United States in 2023, with 614.2 robberies per 100,000 inhabitants. The lowest robbery rate in the country was found in Idaho, with 9.5 robberies per 100,000 inhabitants. Crime in the District of Columbia The violent crime rate in the District of Columbia was found to be the highest in the United States, with there being a few reasons for this: Firstly, the population of the District of Columbia is quite low (causing a higher rate of crime), and secondly, issues such as the crack epidemic of the 1990s exacerbated the prevalence of crime in the District. As rising rents and gentrification force more people out of the District, crime is moving into neighboring Maryland and Virginia suburbs, as poorer residents seek more affordable living conditions. Crime in the United States Overall, violent crime in the United States and the District of Columbia today is far below the violent crime rate of the 1990s. While some may feel that crime is on the rise, due in part to media sensationalism in fact, the opposite is true, and the United States is becoming safer over time.