Examining School Shootings at the National and State Level and Mental Health Implications

Since the Columbine school shooting in 1999, there have been over 420 school shootings across the United States. More than 160 of these shootings occurred after the onset of the COVID-19 pandemic, indicating a significant increase. While 2024 marked the beginning of a decline in the number of mass shootings per year since the onset of the pandemic, this trend did not apply to school shootings, the number of which remains consistently high to date. Although school shootings continue to account for a small portion of total firearm violence, they can have a widespread impact that goes beyond physical harm. According to the Washington Post, at least 390,000 students were exposed to a school shooting (exposure is defined as students attending a school at which a shooting occurred during the current school year) since the 1999 Columbine shooting.

This brief analyzes the rate of student exposure to school shootings over time. While these exposures often occur at the community level, this brief quantifies exposures at the state and national level in order to draw comparisons. Individual state policies may play a role in their exposure rates. A KFF analysis found that states with more restrictive firearm laws generally have lower youth firearm morality than states with fewer firearm laws. The rate of exposure to school shootings depends on factors including school enrollment size and state population size. Therefore, even a single school shooting incident in a state can impact many youths beyond those that are physically injured and may significantly increase exposure rates. Key findings include:

• The U.S. average yearly rate of student exposure to a school shooting has increased threefold over time (from 19 per 100,000 students in 1999-2004 to 51 in 2020-2024).
• From 2020 to 2024, the rate of school shooting exposure per 100,000 students was highest in Delaware (359), DC (356), Utah (166), Arkansas (130), and Nevada (127).
• Children exposed to gun violence may experience serious adverse effects, including anxiety, PTSD, suicide risk, and substance use issues. Some safety measures at schools, such as active shooter drills, may also negatively affect student mental health.

How has exposure to school shootings changed over time among U.S. students?

Since 1999, the rate of U.S. students exposed to a school shooting has nearly tripled, with most of the increase occurring during the pandemic years (2020-2024) (Figure 1). KFF analysis of the Washington Post’s school shooting database found that the average yearly rate of student exposure to school shootings grew from 19 per 100,000 in 1999-2004 to 51 in 2020-2024.

Delaware, the District of Columbia, Utah, Nevada, and Arkansas had the highest rates of students exposed to school shootings since the pandemic. These states have experienced student exposure rates that are at least double the U.S. average yearly rate of exposure (51 per 100,000 students) from 2020-2024. The rate per 100,000 students was highest in Delaware (359), DC (356), Utah (166), Arkansas (130), and Nevada (127) (Figure 2). Note that student exposure rates can vary greatly at the state level due to factors such as school student enrollment size and state population. For example, Delaware and DC had low student populations (under 200,000) from 2020 to 2024, making their exposure rates more volatile than in higher-population states, and a small number of shootings could produce a high rate. For more information, see Methods.

While student exposure to school shootings spiked during the pandemic, several states, including Washington state and Maryland, have had exposure rates higher than the U.S. average for the past several decades (Figure 3). Since 1999, Washington’s exposure rates have remained at or above national average exposure rates – including the state’s lowest average yearly rate in 2010-2014 (25 per 100,000 students) to the state’s highest average yearly rate in 2020-2024 (62). Similarly, Colorado, Maryland, North Carolina, and Nevada have often endured school shooting exposure rates that are higher than the national average rate. Some states have consistently experienced increases in exposure rates over time, including Florida (from a yearly average of 13 per 100,000 students in 1999-2004 to 52 in 2020-2024) and Georgia (from a yearly average rate of 12 in 1999-2004 to 76 in 2020-2024).

In contrast, Maine, Vermont, West Virginia, and Wyoming have had no student exposure to school shootings since 1999. However, there may have been incidences of gunfire on school grounds in these states that did not meet the Washington Post’s criteria for school shootings.

How do exposures to school shootings and efforts to mitigate them affect student mental health and well-being?

Although school shootings account for a small portion of gun violence, they are linked to negative mental health consequences for students and communities at large. Youth antidepressant use and suicide risk can increase in communities with exposures to school shootings. More broadly, exposure to gun violence is linked to post-traumatic stress disorder and anxiety, in addition to other mental health concerns among youth. Gun violence may also lead to challenges with school performance, including increased absenteeism and difficulty concentrating. Additionally, a survey prior to the pandemic found that the majority of teenagers and their parents felt at least somewhat worried that a school shooting may occur at their school. Although research is limited on how mass shootings affect individuals not directly exposed to them, current literature suggests that information and knowledge of mass shootings may be linked to increased levels of fear and anxiety.

Measures intended to combat school violence – such as the placement of school officers and the use of metal detectors – may also negatively affect the well-being of students and their sense of safety. Fifty-four percent of public schools reported having a sworn law enforcement officer (SLEO) such as a police officer or school resource officer on campus during the 2023-2024 school year. While many public schools report feeling that SLEOs have a positive impact on the school community, evidence that they reduce gun violence or school shootings is lacking. Further, among school shootings that involved a SLEO, several involved the officer shooting an unarmed student or staff member. Although nearly all (92%) public schools with SLEOs report that these officers carry a firearm, just over half of these schools have a written policy for firearm handling expectations among SLEOs. Further, the placement of these officers on school campuses may negatively impact students of color specifically, as they are more likely to face disciplinary action than their White counterparts. Separately, 8% of public schools report having metal detectors at school gates for all or most students and 14% of public schools perform random metal detector checks on students. While these detectors are used as a security measure, there are not enough data to demonstrate that they decrease the risk of violent behavior on school grounds. Additionally, the presence of metal detectors may damage students’ sense of safety at school.

Other safety measures include written action plans and drills in the event of an active shooter, with the latter being linked to psychological harm among participants. While 98% of public schools had a written procedure to handle an active shooter during the 2023-2024 school year, only 27% of these schools reported feeling “very prepared” for an active shooter situation. Additionally, many public schools drill students on emergency lockdown and evacuation procedures for school shootings with varying degrees of intensity, with some being psychologically harmful to participants. A longitudinal study on children exposed to school shootings in Texas demonstrated that even when school shootings do not result in deaths, the impacts of gun violence at schools – such as chronic absenteeism and economic consequences – can follow children into early adulthood. Similarly, when schools properly execute a plan prepared in advance, physical and mental harm is not completely preventable. For example, in the recent shooting at a Madison, Wisconsin school, officials praised the well-executed response by authorities, but injury and death occurred regardless.

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