School Shootings in the United States: 1997–2022

To accomplish the aim of our study, we drew on 2 publicly available datasets whose data would allow us to tabulate the frequency of school shootings and school mass shootings from the 1997–1998 school year through the 2021–2022 school year. The databases were selected because they contain complementary data that, when taken together, would provide a longitudinal, comprehensive view of school shootings and school mass shootings in the United States over the past quarter century. Data on school shootings were retrieved from the Center for Homeland Defense and Security’s School Shooting Safety Compendium.¹²  Data on school mass shootings were retrieved from the US Mass Shootings, 1982–2023 database, developed by Mother Jones.¹³  Two noteworthy challenges that exist when studying school shootings and school mass shootings are the lack of a central or unified database that contains all incidents of gun violence in the United States, and the varied definitions used, within disparate databases, for what constitutes respective datapoints—for example, what counts as a school shooting or a school mass shooting.¹⁴  For the purposes of this study, we followed the definitions provided in each respective database for the outcome of interest. As such, in our study, a “school shooting” constituted “each and every instance a gun is brandished, is fired, or a bullet hits school property for any reason, regardless of the number of victims, time of day, or day of week”; incidents are cataloged in the database when they are noted in news reports published in print or online, and all specified incidents were included in our study.¹²  Similarly, in our study, a “school mass shooting” was a shooting noted to have occurred at a kindergarten through 12th grade school site during which 3 or more victims were killed (shootings that occurred before January 2013 were counted if 4 or more victims were killed, pursuant to the operational definition of “mass shooting” that was in place at the time the database was initiated).¹³  Again, all specified incidents in the database were included in our study. The analyses we conducted drew on incidents logged in each respective database in accord with these definitions. Data presented are holistic, as tabulated from each respective data source and calculated for each school year (which we denoted as July 1 through June 30). Results are presented descriptively.

Across the 1997–1998 to 2021–2022 school years, there were 1453 school shootings. The number of school shootings in the United States within a given school year has increased noticeably over the past 25 years, with the number of incidents per year initially appearing to be somewhat steady, then declining slightly, but then rising sharply in more recent years (Fig 1). The number of school shootings in a given school year numbered between 15 and 328, with a low of 15 occurring during the 2009–2010 school year and a high of 328 occurring during the 2021–2022 school year. The most recent 5 school years reflected a substantially higher number of school shootings than the previous 20 years. Over the latest 5 school years—that is, across the 2017–2018 to the 2021–2022 school years—there were 794 school shootings. That was 135 more than the number of school shootings that occurred across the previous 15 school years combined (n = 659).

Although the number of US school shootings has substantially increased in recent years (Fig 1), US school mass shootings have not increased in parallel (Fig 2). There was a total of 11 school mass shootings across the 1997–1998 to 2021–2022 school years. A school mass shooting occurred in 8 of the 25 school year periods examined, with 2 school mass shootings occurring in 3 of the last 25 school year periods examined. There were 17 school years when no mass shooting occurred, whereas no more than 2 school mass shootings occurred during a given school year.

Across the 1997–1998 to 2021–2022 school years, a total of 122 people were killed and 126 were injured in the 11 school mass shootings that occurred, for a total of 248 victims (Fig 3). On average then, over the 25-year time span examined, there were approximately 5 fatalities and 5 injuries per school year that could be attributed to school mass shootings. The greatest number of fatalities and injuries sustained from school mass shootings, combined, was in the 2017–2018 school year, with 27 fatalities and 30 injuries. The 2021–2022 school year had the second greatest number of fatalities and injuries sustained from school mass shootings, combined, with 25 fatalities and 24 injuries. The most recent 10 years had more fatalities and injuries (n = 141) than the previous 15 years (n = 107), with 34 more victims overall. As such, although the number of school mass shootings did not dramatically increase over the 25-year period spanning the 1997–1998 to 2021–2022 school years—in contrast to the number of school shootings more generally—school mass shootings became more deadly. For example, there were 7.6 fatalities per school mass shooting event (n = 5) from 1997–1998 to 2011–2012, compared with 14 fatalities per school mass shooting event (n = 6) from 2012–2013 to 2021–2022. Thus, the number of deaths per mass shooting event has effectually almost doubled when comparing the most recent school mass shooting events with those that occurred earlier.

Rates of gun violence in the United States continue to rise and, as a consequence, so do deaths resulting from that gun violence.^9,15  School shootings on the premises of U.S. kindergarten through twelfth grade schools are at their highest recorded levels. School-related gun violence and school mass shootings continue to be a serious public health concern, uniquely affecting youth within the United States.¹⁶  In the discussion that follows, we draw on our findings and connect them to recent scholarship to consider the implications of increased school-related gun violence, including the psychological trauma that coincides with the rising prevalence of school shootings and the increased deadliness of school mass shootings in the United States.

The prevalence of school shootings and school mass shootings induces trauma in school-aged youth. Coping with the aftermath of violence—including school shootings and school mass shootings—is stressful and exacerbates that trauma. Children and adolescents directly exposed to violence and crime face a host of ancillary challenges, including drug and alcohol use and abuse, depression, anxiety, posttraumatic stress disorder, school failure, and involvement in criminal activity.^4,17 –19  Moreover, youth indirectly exposed are peripherally impacted through extensive media coverage of school shootings and school mass shootings; this leads to more people suffering the effects of these tragedies, with resultant outcomes tied to worsened mental health consequences among members of communities in which gun violence occurs.^18,20 

Traumatic events—proximal or distal—affect youth’s development and well-being. Yet, schools often lack the financing for resources, student support programs, and personnel to provide students with optimal care. That is, schools sometimes struggle to meet the demands of students’ mental health needs even as the prevalence of school shootings increases and as the consequences of school mass shootings become more dire.²¹  Successful school-based interventions and responses are possible, and they can lessen the probability of further trauma among youth impacted by gun violence.²²  Such interventions are needed in addition to broader policy changes and further restrictions in access to firearms.¹⁶ 

After the shooting at Sandy Hook Elementary School in 2012, President Obama promised to fund hundreds more school resource officers (SROs) and school-based mental health specialists across the nation.²³  In the wake of the Sandy Hook tragedy, more than 450 bills were introduced in state or federal legislatures with a focus on school safety.^9,24,25  To reduce violence and improve school safety, schools have relied increasingly on heightened security measures, including increased numbers of SROs and the implementation of zero-tolerance policies (including exclusionary and aversive measures). Despite their prevalence, however, research suggests that the presence of SROs has not decreased school shootings.^26,27  Similarly, though initially designed to reduce gun violence in schools, zero-tolerance policies have been broadened to cover a variety of incidents (eg, threats, bullying). Despite best intentions, these policies have generally failed to stop school shootings and other forms of violence.^28,29  Instead, such policies have increased the number of times students interact with law enforcement in and around schools.

Along with armed security, schools throughout the nation are teaching their students how to “run, hide, or fight” if approached by an active shooter.¹⁶  During Alert, Lockdown, Inform, Counter, and Evacuate drills, students are frequently exposed to unavoidable and frightening images and stories of school violence.³⁰  They are subject to active shooter drills that may not be effective and, in some cases, may themselves actually induce trauma. Simulation drills expose students to aggressive and frightening elements—for example, the use of fake blood, the shooting of guns loaded with blanks or rubber pellets, and the false pretense that it the occurrence is not a drill but an actual attack.^16,31  Despite the potential for induced fear, anxiety, and trauma to come from these drills, school administrators view these activities as a suitable response to parental demands to keep children safe.^16,32  Whatever benefit physical security, active shooter drills, and SROs may have in safeguarding students, imposing fortress-like settings on youth can increase fear and introduce trauma rather than reduce it.^16,33,34  In effect, the supports designed to keep students safe may be inadvertently doing harm to their mental health. To enhance efforts to support student safety, district and school leaders must aspire to implement discrete security measures to prevent gun violence and school shootings, for example, through environmental design.^16,35,36 

Although security measures surely play an important role in protecting students from gun violence, it may be insufficient to focus only on shooting prevention through “hardening the target”¹⁶ —that is by making school sites more secure to preemptively mitigate disaster. Prevention starts long before a shooter enters a school, and it includes more than just security measures on school premises. Instead, a comprehensive and scientifically supported public health approach is needed to address gun violence and school shootings. The Coalition of National Researchers proposed such an approach for safeguarding both children and adults against gun violence; the approach involves 3 levels of prevention: (1) universal approaches promoting safety and well-being for everyone; (2) practices for reducing risk and promoting protective factors for persons experiencing difficulties; and (3) interventions for individuals where violence is present or appears imminent.³⁷ 

Recently, the framework of Multi-Tiered Systems of Supports (MTSS)—including Positive Behavioral Interventions and Supports and Response to Intervention—has been implemented in schools.^{9,38,39,40,41}  This evidence-based framework enables school personnel to address students’ educational, social, emotional, and behavioral needs. The Center on Positive Behavioral Interventions and Supports offers a wealth of resources and implementation strategies, and also provides information about data-driven decision-making, integration of evidence-based behavioral and academic interventions, preventive measures, culturally sensitive practices, and mental health support.^41,42  Schools should consider the implementation of MTSS as a means to counter the threat of gun violence, school shootings, and school mass shootings because it reduces reliance on exclusionary and aversive measures like zero-tolerance policies, seclusion and restraints, corporal punishment, and school-based law enforcement referrals and arrests. Instead, MTSS engenders support for students’ well-being, improves school climate, and supports reductions in behavioral issues and school violence.^9,43 

This study, like any empirical inquiry, has some limitations that should be considered as its results are interpreted. First, the databases used for this study were compiled directly from news reports and other publicly available or publicly reported information. Although the authors of each respective database have endeavored to do their due diligence to verify the accuracy of the data compiled in their database, because of reliance on public reporting, there is certainly the potential for undercounting the number of school-related gun violence incidents that occurred each year. As media attention on gun violence has increased over the years, there is also the potential for the number of reported incidents each year to be higher, such that incidents overall may not have increased or be increasing, but rather the observed increases may be an artifact of more attention paid to this issue by news media in more recent years. Given the similar national trends in gun violence and gun-related deaths, however, this explanation seems unlikely.^15,44 

The analyses in this study were also limited by and linked to the definitions of school shootings and school mass shootings as delineated in the databases from which we drew for the study’s data. This naturally constrained our ability to consider these outcomes from vantage points that are either beyond the scope or different in scope from those advanced by and reported in each respective database.¹⁴  There is no singular national database that contains all pertinent information and complete statistics on school shootings and school mass shootings. This limits researchers’ ability to conduct empirical analyses on school shootings and school mass shootings.

These limitations notwithstanding, the analyses we conducted did provide new insights into the issue of school shootings and school mass shootings across a recent 25-year span, school years 1997–1998 through 2021–2022. Rates of school shootings have increased, and school mass shootings have become more deadly. In light of these results, we considered the effects of these increasing rates and risks associated with school-related gun violence for the nation’s youth, who have spent their entire lives attending schools marked by the specter of school shootings and school mass shootings.

Gun violence in United States is a public health crisis affecting the nation’s youth. School shootings have risen in frequency in the recent 25 years, and they are now at their highest recorded levels. School mass shootings, while they have not necessarily increased in frequency, have become more deadly. This public health crisis leads to detrimental outcomes for all the nation’s youth—not just those who experience school-related gun violence firsthand. School-based interventions can be used to address this public health crisis, and effective approaches such as MTSS and services should be used in support of students’ mental health and academic and behavioral needs.

MTSS

Multi-Tiered Systems of Supports

SRO

school resource officer