The Landscape of School Active Shooter Drills and Other School Security Measures

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National Academies of Sciences, Engineering, and Medicine; Division of Behavioral and Social Sciences and Education; Committee on Law and Justice; Board on Children, Youth, and Families; Committee on the Impact of Active Shooter Drills on Student Health and Wellbeing; Hutton R, Bonnie RJ, editors. School Active Shooter Drills: Mitigating Risks to Mental, Emotional, and Behavioral Health. Washington (DC): National Academies Press (US); 2025 Oct 17. School Active Shooter Drills: Mitigating Risks to Mental, Emotional, and Behavioral Health. Show details National Academies of Sciences, Engineering, and Medicine; Division of Behavioral and Social Sciences and Education; Committee on Law and Justice; Board on Children, Youth, and Families; Committee on the Impact of Active Shooter Drills on Student Health and Wellbeing; Hutton R, Bonnie RJ, editors. Washington (DC): National Academies Press (US) ; 2025 Oct 17. Contents Hardcopy Version at National Academies Press Search term < Prev Next > 2 The Landscape of School Active Shooter Drills and Other School Security Measures School safety and security measures generally encompass a wide range of tools, interventions, practices, and policies that work in tandem to ensure that schools, students, teachers, and staff are safe. They also equip school communities with reasonable emergency preparedness and response tools in anticipation of a wide variety of potential health and security concerns. These policies and practices range from firearm violence prevention and fire safety to preparation for weather-related emergencies and deterrence of bullying. Schools across the United States implement tactics and policies specific to firearm violence prevention and preparedness, including active shooter drills. This report focuses primarily on mitigating the potential adverse mental, emotional, and behavioral health outcomes resulting from implementing school active shooter drills. In accordance with its statement of task ( Box 1-1 in Chapter 1 ), however, the committee also reviewed other commonly used security interventions and policies being implemented in K–12 schools that might influence or shape existing procedures for school active shooter drills—including the use of metal detectors and the presence of school resource officers and other school security personnel. Building on the foundational terminology, key concepts, and conceptual framing introduced in Chapter 1 , this chapter provides an overview of active shooter drills and other school security measures currently used in K–12 schools in the United States. The chapter begins by situating school active shooter drills and other school security measures in the broader context of a comprehensive approach to school safety. Such an approach encompasses not only drills and other security measures but also interventions that support students' mental, emotional, and behavioral health; these include promoting positive school climate, social-emotional learning, restorative and trauma-informed practices, and access to school-based health professionals. The chapter then describes the current landscape of school active shooter drills, including the federal and state mandates that guide them. Finally, the chapter reviews the implementation of other school security measures in K–12 schools in the United States, highlighting their variations. This examination of these practices informs the committee's assessment of evidence regarding potential adverse outcomes in these domains and serves as the foundation for the committee's recommendations for school leaders, legislators, and decision-makers in Chapter 6 and the future research agenda set forth in Chapter 7 . CONTEXT OF SCHOOL SAFETY School active shooter drills and other school security measures are best understood as components of a comprehensive school safety approach. The U.S. Department of Justice defines comprehensive school safety as a holistic approach to creating a secure, inclusive, and supportive learning environment that protects students, staff, and visitors from various threats, hazards, and risks; this approach integrates multiple aspects of safety, including physical, emotional, social, and environmental well-being, and is guided by policies, practices, and programs that foster a positive school climate and positive student behavior ( U.S. National Institute of Justice, 2020 ). A comprehensive school safety framework typically includes the following elements: Prevention and preparedness —implementing proactive measures such as school policies, emergency planning, bullying prevention, and mental health support to reduce risks before they occur. Prevention activities include all efforts to promote a positive and trauma-informed school climate, including teaching and modeling social-emotional skills, applying a trauma-informed lens, setting behavioral expectations, supporting student mental health, and addressing bullying. Protection and security —policies and practices that secure or safeguard students, staff, visitors, and property from threats or hazards. These measures include conducting suicide risk and threat assessments; creating safety plans for individual students; conducting drills; ensuring visible signage and emergency exits; ensuring the physical security of school facilities through controlled access, surveillance, and door lock policies; and collaborating with law enforcement. Health and well-being —supporting the mental and physical health of students and staff through counseling, social-emotional learning, and wellness programs. Mitigation —minimizing the impacts of threats or hazards and reducing the likelihood that threats and hazards will occur. Mitigation efforts include preplanning about what to do in case of an emergency, including determining and practicing the protocols for each type of response (i.e., lockdown, shelter in place, and evacuation). Additionally, mitigation activities include establishing partnerships with emergency services and conducting assessments that identify vulnerabilities in the built environment, as well as emergency response activities. Assessment results may identify appropriate actions to take such as securing access points, using metal detectors or video cameras, and employing other physical safety measures. Response and crisis management —encompasses the immediate actions taken during an emergency to stabilize the situation and save lives and property. Response activities include activating the emergency response plan, including specifying the type of emergency response required, contacting and coordinating with emergency responders, and communicating with families and the broader community, as is possible. Recovery and resilience —providing resources and support to help students, staff, and the school community recover from crises, trauma, or disasters and restore the learning environment to normalcy by attending to the physical environment, academic routines, and the emotional well-being of students and staff. Recovery activities include providing crisis and mental health support, ensuring open and transparent communication about the event, debriefing the event, and engaging in activities that foster connection and support. Supportive environment —promoting well-being and a sense of belonging to ensure that all students feel safe and valued. A comprehensive school safety strategy is typically based on the Whole School, Whole Community, Whole Child approach, aligning national and local education policies, emergency management guidelines, and public health initiatives into an operational framework that schools can apply to address the safety, security, and wellbeing of their students ( Centers for Disease Control and Prevention, 2021 ). In the context of comprehensive school safety, some efforts are geared more specifically toward preventing a potential threat, whereas others are in place specifically to react/respond to an active threat ( Mayer et al., 2021 ). Generally, preventive measures are taken to avoid incidents before they occur (e.g., physical barriers, security training for staff, behavioral threat assessment processes). Reactionary measures are responses implemented during or after an incident. A public health framework conceptualizes different types of prevention and their role in keeping schools safe ( Mayer et al., 2021 ; Rajan et al., 2022 ). However, the available evidence bearing on the effectiveness of many of these safety policies and tactics varies and ought to be considered in that light ( Rajan et al., 2022 ). Primary prevention entails strategies aimed at preventing the occurrence of firearm-related incidents before they emerge as credible threats to a school community. Secondary prevention comprises measures for addressing and managing incidents when they occur (e.g., door locks). Tertiary prevention encompasses interventions aimed at minimizing the harms and impacts of incidents after they occur (e.g., grief counseling services). In this framing, preventive and reactionary safety measures overlap, and an assessment bearing on when use active shooter drills requires understanding their specific role as an emergency preparedness (secondary prevention) tool. In the committee's view, a comprehensive approach to school safety requires a balance between preparedness for immediate threats and long-term prevention strategies that address the root causes of violence. Schools that focus too narrowly on active shooter drills may miss opportunities to prevent violence before it occurs. By focusing not only on physical safety but also on positive school climate through social-emotional learning and trauma-informed practices, schools can create an environment that both responds to threats and works actively to prevent them. These interventions are crucial for promoting prosocial behaviors, modeling conflict resolution, and fostering positive student relationships. Among many other benefits, they play an essential role in reducing instances of violence and aggression and anchoring a comprehensive school safety plan. The next sections briefly describe these concepts and summarize findings from available research related to prevention strategies typically implemented in K–12 schools across the country; Table 2-1 summarizes these points briefly. Program implementation varies significantly, and individual schools and school districts vary considerably in their ability to build this kind of programming into their curricula, based on financial and staff resources and student needs. TABLE 2-1 Preventive Strategies for Ensuring School Safety. The Importance of School Climate In its simplest form, school climate refers to “the quality and character of school life” ( National School Climate Center, 2007 ). The U.S. Department of Education (ED) expands on that definition and observes that a “positive school climate includes policies and practices that foster school safety for all; promote a supportive academic, disciplinary, and physical environment, and encourage and maintain respectful, trusting, and caring relationships throughout the school community” ( Office of Planning, Evaluation, and Policy Development, 2023 , p. 7). A positive school climate helps to promote and maintain the physical and psychological safety of both students and staff, thereby contributing to an environment that supports desired student behaviors (e.g., respectful communication), while reducing problematic behaviors (e.g., bullying, threats of violence). Research has shown that a positive school climate and positive student behaviors are essential to school safety and violence prevention (see, e.g., Center on Positive Behavioral Interventions and Supports, n.d. ; Ice et al., 2015 ). Students who feel connected to their school are less likely to engage in violent behavior ( Dow-Fleisner et al., 2023 ), experience bullying ( Dow-Fleisner et al., 2023 ; Smalley et al., 2017 ), or suffer from emotional distress ( Lester & Cross, 2015 ). Additionally, desired student behaviors, such as respect for teachers and peers and compliance with school rules, lead to safer school environments ( Cornell & Mayer, 2010 ). Social-Emotional Learning Strategies such as social-emotional learning can be employed to create a positive school climate by nurturing students' emotional intelligence, social skills, and self-regulation. Extensive research shows that these programs can reduce behavioral problems and improve social-emotional skills and indicators of well-being (e.g., academic success, prosocial behaviors), contributing to overall school safety ( Durlak et al., 2011 ; Taylor et al., 2017 ). Social-emotional learning refers specifically to the process through which all young people and adults acquire and apply the knowledge, skills, and attitudes to develop healthy identities, manage emotions, achieve personal and collective goals, feel and show empathy for others, establish and maintain supportive relationships, and make responsible and caring decisions ( Collaborative for Academic, Social and Emotional Learning [CASEL], n.d. ). As specified in the CASEL framework, these skills include five essential capacities: self-awareness, self-management, healthy relationships, social awareness, and responsible decision-making. Broadly speaking, these skills encompass the ability to recognize and regulate emotions, advocate for oneself, develop empathy, resolve conflicts peacefully, and consider others' perspectives. For example, bullying and victimization prevention programs that are grounded in principles of social-emotional learning aim to build students' skills in emotion regulation, prosocial behavior, and capacity for empathy as strategies for reducing aggression and fostering a supportive school environment ( Espelage et al., 2015 ; Farrington et al., 2019 ; NASEM, 2016 ). Positive behavioral interventions and supports is another well-established and evidence-informed framework for improving student behavior through a tiered system of support, focusing on proactive measures and data-driven decision-making. Several studies have demonstrated that implementing this framework can help reduce disciplinary incidents and improve school climate overall ( Bradshaw et al., 2012 ). Problematic student behavior is often the result of a skill deficit(s) in social-emotional competencies. Therefore, to increase desired behaviors among students and build a positive school climate, schools need to ensure that these skills are consistently taught and modeled by staff and administrators. Restorative and Trauma-Informed Practices In addition to a lack of or a deficit in social-emotional skills, behavior can also be anteceded by previous traumatic experiences. Individuals who have experienced trauma, such as abuse, neglect, or witnessing a violent event, often have difficulty regulating their emotions and behavior ( Maynard et al., 2019 ) and may engage in behaviors that can be viewed as unpredictable, volatile, or extreme ( National Child Traumatic Stress Network [NCTSN], n.d. , 2022 ; see also Chapter 5 ). These behavioral responses are tied to the limbic system's physiological responses of “fight,” “flight,” or “freeze” when faced with a perceived threat. To support students who have experienced trauma and to ensure that all students are in an emotionally regulated state for learning, some schools are implementing restorative and trauma-informed practices. Restorative practices emphasize repairing harm and building community. Studies suggest that restorative practices can reduce suspensions and improve school climate, which may indirectly enhance security ( Gregory et al., 2016 ). Additionally, dating violence prevention programs are designed to prevent and address dating violence among students, providing education on healthy relationships and intervention strategies. Evidence suggests that these programs can reduce incidents of violence generally and improve students' understanding of healthy relationships ( Foshee et al., 2004 ). Trauma-informed practices are not explicitly a type of program; they are best understood as a set of practices that allow school staff, teachers, and leadership to recognize and respond to the effects of trauma on students' behavior and learning, aiming to create a supportive and empathetic school environment ( NCTSN, 2018 ). Extensive research supports the ability of trauma-informed approaches to improve behavioral outcomes and academic performance for students who have experienced trauma ( Cohen & Mannarino, 2015 ). Incorporating trauma-informed practices into the school and classroom settings allows educators to better understand trauma and its impact and to respond appropriately when both they and their students are exhibiting signs of dysregulation ( Avery et al., 2021 ; Cafaro et al., 2023 ). And integrating trauma-informed practices has been documented in research literature as part of an evidence-informed school safety strategy ( Asmussen et al., 2019 ; Brueck, 2016 ; Rajan et al., 2022 ; Rones & Hoagwood, 2000 ; Weist & Evans, 2005 ). Access to Mental Health Services Extensive research shows that access to school counselors, school social workers, school psychologists, and other trained mental health professionals can improve the mental health and well-being of both students and staff and plays a critical role in reducing the likelihood of aggression and violence in schools and fostering the healthy development of children and youth ( Hoover & Mayworm, 2017 ; Rossen & Cowan, 2014 ; Tomé et al., 2021 ). However, many K–12 schools lack the staff and resources needed to support these services. Indeed, there is a national shortage of school-based health and mental health professionals, which limits the capacity of schools to support students' health and well-being ( Gratz et al., 2023 ; Nwabuzor, 2007 ; Willgerodt et al., 2024a , b ). A 2023 national survey on school safety found that 60% of K–12 school leaders identified student mental health challenges as the greatest threat to school safety, and more than half of respondents reported feeling unprepared to address this challenge ( Raptor Technologies & National Association of School Resource Officers [NASRO], 2023 ). Staffing guidelines from both the American School Counselor Association (ASCA) and the National Association of School Psychologists (NASP) further underscore the scope of this shortage. The ASCA (2024) recommends one school counselor for every 250 students; however, the national average in 2023–2024 was one for every 376. Similarly, the NASP (2023) recommends a ratio of one school psychologist for every 500 students, but the national average is approximately one school psychologist for every 1,127 students. These shortages impact service delivery in K–12 schools. Data from the National Center for Education Statistics ( NCES, 2024 ) reveal that, during the 2023–2024 school year, only 48% of public schools reported being able to meet the mental health needs of all students who needed support—a nearly 10% decline from 2021 to 2022. Insufficient staffing (55%), inadequate funding (54%), and limited access to licensed mental health professionals (49%) were cited as barriers to providing mental health services. In addition, fewer schools reported drawing on federal funding sources to support these services ( NCES, 2024b ). Workforce and staffing shortages extend beyond traditional mental health. National data show that only about two-thirds (65.7%) of schools have access to a full-time school nurse, with access significantly lower in rural (56.2%) compared with urban (70.3%) areas ( Willgerodt et al., 2024a ). These disparities can limit the broader range of student supports that school health professionals often facilitate. School-based health professionals are integral not only to physical and mental health services but also to broader student support systems. These professionals frequently serve as connectors—helping to identify unmet material needs and guiding students and families to additional services. Whether through coordinating with other staff, initiating referrals, or managing programs that supply basic necessities, these professionals help reduce barriers to care and supports that promote health and positive educational outcomes ( Kjolhede et al., 2021 ; NASP, 2021b ). THE LANDSCAPE OF ACTIVE SHOOTER DRILLS As described in Chapter 1 , the implementation of active shooter drills in schools has become increasingly common in the United States, driven by the rising number of school shooting incidents and growing public concern about school safety. State-mandated school active shooter drills are intended to prepare students, staff, and communities for potential incidents by outlining specific protocols and practices. However, these requirements vary significantly in scope and detail, highlighting differences in state resources, legislative priorities, and local approaches. Some states and localities prioritize the frequency of drills and the role of external stakeholders such as law enforcement, while others provide detailed guidance on drill procedures and rely more heavily on training for school staff. Differences in drill frequency, type, and participant accommodations underscore the need for thoughtful implementation that achieves preparedness while protecting the well-being of participants. Many schools face disparities in resources and infrastructure that affect their ability to implement effective safety strategies, including active shooter drills. The complex landscape of school active shooter drills includes state mandates; logistical considerations; and the mental, emotional, and behavioral impacts on students and staff. Each of these topics is discussed in detail in the sections that follow. State Mandates for School Active Shooter Drills The number of school active shooter events has been increasing since the early 2000s. While these events remain statistically rare, they have a profound impact on communities and school systems. A number of state legislatures have responded by mandating the implementation of active shooter drills in schools to prepare for the possibility of an active shooter event ( Blair et al., 2013 ; Martaindale & Blair, 2019 ; Rygg, 2015 ). According to reporting from ProPublica, as of early 2024, at least 37 states required K–12 schools to conduct school active shooter–related drills, typically on an annual basis ( Churchill & Kriel, 2024b ) (see Figure 2-1 ). Although 13 states do not have mandates for such drills, school districts in these states may conduct them voluntarily. FIGURE 2-1 States that require schools to carry out active shooter–related drills, as of February 4, 2024. SOURCE: Churchill & Kriel, 2024. Most statutes focus on the logistics of a drill, such as whom they should include (e.g., local law enforcement officials and personnel at each school) ( Blair et al., 2013 ; Martaindale & Blair, 2019 ; Rygg, 2015 ). For instance, Illinois legislation mandates that all schools (i.e., public, private, and charter) perform school active shooter drills with local law enforcement. In addition, some states prescribe who should be involved in the development and planning of active shooter drills. In Texas, for example, legislation passed in 2021 (Tex. S.B. 168, 2021) requires schools to plan drills with input from first responders, mental and behavioral health professionals, students, families, and school staff. Some states require specific types of school active shooter drills or have promulgated guidelines on how the drills should be implemented. Missouri, for example, enacted the “Active Shooter and Intruder Response Training for Schools Act” in 2013, which requires all school personnel (i) to participate in simulated active shooter and intruder response drills that are led by certified law enforcement professionals and (ii) to conduct annual training for teachers and school personnel on responding to students who report threatening situations and addressing scenarios involving dangerous or armed intruders (Mo. S.B. 75, 2013). In 2025, Missouri updated its legislation with House Bill 416, which mandated that initial annual training sessions last 8 hours and that subsequent annual sessions last 4 hours. Most state mandates specify how often drills should be performed. For example, Nevada requires that school active shooter drills take place five to six times every school year, Minnesota five times every school year, and Oklahoma and New York four times every school year. Other states require drills only once or twice every school year or do not designate frequency in their mandates. Table 2-2 shows the variation in frequency of school active shooter drills required by state mandates. TABLE 2-2 Frequency of School Active Shooter Drills Required by State Mandates, February 4, 2024. Comprehensive explanations from state or local agencies regarding active shooter drills and training policies remain limited. However, recent reporting sheds light on the decentralized and often fragmented nature of these practices. Many states leave decisions about training requirements for school-based law enforcement to local districts, resulting in inconsistent implementation across jurisdictions ( Churchill & Kriel, 2024b ). Reports from The Texas Tribune and ProPublica suggest that financial and logistical barriers, particularly in rural or under-resourced areas, may underlie the lack of statewide mandates ( Churchill & Kriel, 2024a , b ). However, these factors are not always explicitly acknowledged. At the same time, concerns over student mental health have begun to influence policy decisions. For example, New York recently introduced a bill to reduce the number of required annual active shooter drills from four to two, citing both the psychological toll such drills can take on students and the lack of compelling evidence that they enhance school safety ( Colon, 2024 ). Collectively, these developments highlight how a combination of resource limitations, policy decentralization, and ethical concerns continues to shape a complex and evolving landscape for school active shooter preparedness. Implementation of School Active Shooter Drills Although state mandates for school active shooter drills vary, schools often have discretion to specify how the drills are defined, implemented, and practiced. Information on how frequently different types of drills are used in practice is limited. Even when statutory requirements exist, how requirements are interpreted and carried out at the school level varies widely, including differences in planning procedures, participation, and notification practices. Variations in how school active shooter drills are implemented may be influenced by differences in resources (e.g., finances, faculty and staff turnover), community contexts, and the developmental needs of students ( Lindstrom Johnson, 2009 ; Sprague & Walker, 2021 ). Organization and Planning States and localities vary as to who organizes and implements these drills. In some localities, school administrators employ private companies to facilitate active shooter response training. In other cases, local law enforcement or school resource officers organize and implement the drills. In still other jurisdictions, drills are organized and implemented by the school leaders or school safety teams ( Blair et al., 2013 ; Martaindale & Blair, 2019 ; Tex. S.B. 168, 2021). Participation In some states, a student or group of students may be permitted to opt out of a planned active shooter drill. Conversely, some cities, counties, districts, and localities do not provide opportunities to opt out, requiring all students, faculty, and staff to participate ( Doss & Shepherd, 2015 ; NASP et al., 2021 ). The ED (2025) encourages schools to evaluate individual needs and offer accommodations or alternative activities (e.g., discussion-based practices) for students unable to participate in some standard drills, stressing that schools need to collaborate with families and multidisciplinary teams to identify and implement these accommodations. Schools also vary in the degree to which educators and school staff participate in school active shooter drills. For instance, some schools engage school mental health professionals in these drills. As discussed in detail later in this report, evidence suggests that integrating mental health professionals and services in these drills could be beneficial and mitigate potential harm or trauma that students, faculty, staff, families, and community stakeholders may experience during these drills ( Dickson & Vargo, 2017 ; NASP et al., 2021 ). Of course, as previously noted, the availability of additional school staff or community partners to participate in school active shooter drills varies based on a school's or community's resources and geography. In rural schools, for instance, access to emergency first responders or proximity to law enforcement, health care providers, and other community resources may be limited and restricted because of geographic isolation ( Nickerson & Schildkraut, 2024 ; Schildkraut & Nickerson, 2022 ). Under-resourced schools may also lack school mental health providers or school nurses to engage in the planning, implementation, and follow-up for school active shooter drills ( Gratz et al., 2023 ; Lee et al., 2009 ; Ramos et al., 2014 ). Notifications/Announcements Active shooter drills at a school may be publicly preannounced or may occur without being announced to staff, families, students, and community stakeholders. Notifications and announcements may be communicated in various ways, such as in the classroom; in a school assembly; or by email, texts, or social media. Drill Type As described in Chapter 1 , school active shooter drills can take a variety of forms. For example, walkthrough active shooter practices are aimed at helping participants with emergency roles through untimed exercises and discussions. Staff, leaders, first responders, and occasionally students participate to improve coordination ( Blair et al., 2013 ; NASP et al., 2021 ; Rygg, 2015 ). Tabletop exercises include guided discussions aimed at enhancing preparedness, allowing school crisis teams, law enforcement, and—in some cases—students to examine plans and adapt to complex scenarios. These sessions are intended to promote critical thinking and readiness, while allowing participants to engage at their own comfort level ( Gerlinger & Schleifer, 2021 ; NASP et al., 2021 ). By contrast, lockdown drills secure classrooms with locked doors, darkened rooms, and silence, addressing internal threats, while secured-perimeter lockouts protect against external risks. According to the School Survey on Crime and Safety (SSOCS), in school year 2021–2022, 95.5% of all public K–12 schools had conducted a lockdown drill with students that year ( NCES, 2022 ; see Table 2-3 ). TABLE 2-3 Percentage of Public K–12 Schools That Drilled Students on the Use of Emergency Procedures, School Year 2021–2022. Full-scale simulation exercises at school are intended to equip first responders and school leaders with the skills and confidence needed to lead a response to an active shooter event at school, and to test their protocols and identify potential weaknesses, although their implementation varies widely ( Blair et al., 2013 ; Martaindale & Blair, 2020; NASP et al., 2021 ; Rygg, 2015 ). Some are unannounced and include high-sensorial elements (e.g., sounds of gunfire, use of fake blood, simulated violence), while others are organized and announced in advance ( Blair et al., 2013 ; Martaindale & Blair, 2019 ; NASP et al., 2021 ; Rygg, 2015 ). There has been a push for schools to use options-based practices, which originated in law enforcement agencies and focus on independent, in-the-moment decision-making ( Donovan, 2023 ; Miotto & Cogan, 2023 ; NASP et al., 2021 ; Schonfeld et al., 2020 ; Simonetti, 2020 ). Some schools use options-based strategies that have been subsequently adopted for school systems; however, in some cases, practices that were originally developed for adults are used without adaptation in school active shooter drills and do not account for whether they are appropriate for the developmental level of student participants ( NASP et al., 2021 ). For example, guidance from NASP, NASRO, and Safe and Sound Schools emphasizes that students should not be instructed that they are expected to engage (i.e., fight or counter) with assailants in a life-threatening emergency. Research has produced little empirical evidence regarding the mental, emotional, and behavioral health effects of these practices, leaving questions regarding the appropriateness of options-based practices for all students and staff. In addition, there are some indications that these practices may not be suitable for certain age groups, for individuals with severe functional and access needs, or for those with trauma histories ( NASP et al., 2021 ; Safe and Sound Schools, 2016 ). Despite these concerns, options-based practices are included in current federal guidance to schools on responding to an active shooter event, which in some cases includes considerations for developmentally appropriate adaptations ( ED & REMS TA Center, n.d. ; ED et al., 2013 ; Federal Bureau of Investigation, 2024 ). Other schools have implemented the use of standard response practices 10 (described in Chapter 1 ). For each standard response, there are specific student and staff actions. In drills using standard response practices, students and staff physically rehearse consistent, predefined actions needed to respond to an emergency, such as a school active shooter event. The response to practice a lockdown (used to respond to an immediate threat inside of the school), for example, includes the actions of locking the door, turning off the lights, moving out of sight, and remaining quiet. These practices emphasize procedural repetition to reinforce emergency responses ( “I Love U Guys” Foundation, 2023 ). A number of states and local school districts have adapted the “I Love U Guys” Foundation's Standard Response Protocol, a framework that includes five core standard response practices for implementation in schools, or have incorporated it into guidance for schools in response to input from state and national practitioners, including those in New York ( New York State Education Department, n.d. ), Maryland ( Maryland Center for School Safety, 2024 ), and Texas ( Texas School Safety Center, n.d.a ). Frequency School active shooter drills can occur monthly, quarterly, annually, and/or randomly. Some statutes requiring school active shooter drills indicate that frequent drills aim to establish “muscle memory” or “motor learning,” so that students' safety responses and behavior to an active shooter event at school becomes almost instinctive or reflexive ( Gerlinger & Schleifer, 2021 ; Schildkraut & Nickerson, 2022 ). As reported previously in Table 2-1 , there is a great deal of variation across states and schools in how frequently drills take place. However, there is limited information on how frequently different types of drills are carried out in practice. Debrief and Evaluation In some instances, an informational debrief and evaluation is conducted after each active shooter drill at a school; again, the content of such debriefs and evaluations varies greatly across schools. For some schools, debrief and evaluation provides school leaders an opportunity to communicate the successes or failures that occurred during the drill to the school community. For other schools, a debrief and evaluation can be more extensive. For example, students might receive mental health counseling and be provided an optional quiet space to calm down; school leaders might ask participants what went well and what did not. Families might be informed about the occurrence of the drill and be provided with calming strategies and potential resources for mental health care. School administrators might be asked to prepare an after-action review for the school community, evaluating results, identifying gaps, and documenting lessons learned and successes achieved ( NASP et al., 2021 ). LANDSCAPE OF OTHER SCHOOL SECURITY MEASURES In addition to school active shooter drills, the committee was charged with examining “other school security measures” (see the statement of task, Box 1-1 in Chapter 1 ). Security measures comprise strategies and tools implemented to ensure the safety and security of students, teachers, and staff in a K–12 school. They typically aim to prevent or mitigate threats ranging from firearm violence to unauthorized building access. This section organizes school security measures into three categories: surveillance interventions, personnel interventions and training, and physical security interventions. The committee broadens its examination of school security measures beyond metal detectors, door locks, and school security personnel to encompass a wider range of practices and interventions currently used in U.S. schools, in order to provide a more comprehensive view of the existing landscape. Researchers have described such security measures as part of a phenomenon known as “hardening” of schools ( Chambers, 2022 ; Kim et al., 2021 ; Lindstrom Johnson et al., 2018 ; Thompson, 2023 ). The past 2 decades have seen an uptick in school-hardening efforts , defined as physical and procedural modifications for reducing vulnerabilities within a school and preventing or minimizing damage from an attack ( Barroso, 2022 ; Burr et al., 2024 ; Warnick & Kapa, 2019 ). They typically involve enhancing the resilience of buildings and systems against external threats and often also involve physical changes to improve security (e.g., locks, barriers). Along with school active shooter drills, these other security measures are part of a comprehensive school safety and security strategy, which encompasses a range of interventions (including those aimed at improving school climate and student). In their comprehensive review of literature on factors that contribute to school safety, Nickerson et al. (2021) highlight the importance of considering both physical and behavioral aspects of school security and emphasize the importance of school context and climate. Recent literature has become more specific in how it addresses school environment. Stilwell et al. (2024) , in particular, build on the existing evidence base on school safety and violence by proposing a multidisciplinary, comprehensive framework designed to guide research and practice. This framework advocates for the creation of school environments that promote attentiveness and vigilance among school personnel and students as key strategies for preventing violence and improving safety. Table 2-4 briefly describes the various categories of school security interventions and the tactics and policies within each category; it also summarizes findings from the existing research literature. TABLE 2-4 Summary of K–12 School Security Measures. The following subsections describe what is known about how K-12 schools are implementing physical security interventions, surveillance interventions, and personnel interventions and training. Comprehensive, national data on the frequency with which these interventions are being used in schools are limited. However, the School Survey on Crime and Safety (SSOCS), a nationally representative survey conducted by the National Center for Education Statistics (NCES), provides some insights from its recent 2021–2022 school year data collection. These findings, where available, are summarized in the subsections that follow; however, additional data and research are needed to fully understand the scope and use of various security measures in K–12 schools in the United States (see Chapter 7 ). Physical Security Interventions Physical security measures implemented in K–12 schools—such as door locks and access controls (indoor and outdoor), perimeter fencing, reinforced windows, buffer zones, 11 and hard corners 12 —encompass tactics and policies designed to protect schools from unauthorized access, violence, or other physical threats ( Moore et al., 2021 ). These measures, when implemented as part of a broader systems approach are intended to help schools detect, delay, and respond to potential threats. A 2021 synthesis of literature on physical security planning in K–12 schools found that a layered school security model—addressing the potential for threats at the campus perimeter, on school grounds, at the building perimeter, and in interior spaces—is generally regarded as the most effective, particularly when these approaches are aligned with clearly defined policies, staff roles, and training ( Moore et al., 2021 ). Evidence from national surveys and implementation studies suggests that such measures are adopted widely, especially in response to concerns about school shootings and other acts of targeted violence ( NCES, 2024a ; Schwartz et al., 2016 ). Some studies have also explored integrating these physical features with staff training and emergency planning, particularly in the context of drills and lockdown procedures ( Schildkraut et al., 2020 ). Door locks and access controls restrict building access to authorized individuals and enhance lockdown capabilities. According to the SSOCS for school year 2021–2022, approximately 97% of public schools reported controlling access to school buildings during school hours, such as through locked or monitored doors, and about 61% of schools reported controlling access to school grounds during school hours, using measures such as locked or monitored gates ( NCES, 2024a ; see Table 2-5 ). And according to the 2021–2022 data collection, 76.1% of U.S. public K–12 schools reported equipping classrooms with locks so that doors can be locked from the inside. Among schools where at least three-quarters of students qualify for free or reduced-price school lunch, 74.4% had locking doors in their classrooms in the 2021–2022 school year, compared with 78.4% at schools where a quarter or fewer students qualify for free or reduced-price lunch ( NCES, 2024a ). Charter schools were more likely than traditional public schools to have doors that locked from the inside in the 2021–2022 school year (80.0% vs. 75.7%) ( NCES, 2024a ). TABLE 2-5 Percentage of Public K–12 Schools with Controlled Access Security Measures, School Year 2021–2022. While the primary goals of physical security measures relate to restricting access and emergency response, research has also examined their potential influence on school climate. For instance, research suggests that highly visible or restrictive security measures may contribute to increased perceptions of surveillance and reduced perceptions of trust or belonging among students ( Bachman et al., 2011 ; Tanner-Smith et al., 2018 ). These findings are particularly relevant in discussions of school active shooter preparedness, where physical design features such as door locks or hard corners are often deployed as part of school active shooter drills. Taken together, existing literature points to a complex interplay among physical security infrastructure, emergency preparedness practices, and students' perceptions of safety and emotional security within school settings. Surveillance Interventions Specific tactics and policies in the category of surveillance interventions include metal detectors, security cameras (indoor and outdoor), anonymous reporting systems, clear backpack or no backpack policies, locker and person searches and screenings, and behavioral threat assessment processes. According to the SSOCS for school year 2021–2022, approximately 93% of schools used security cameras to monitor the school, 23% implemented random sweeps for contraband, and about two-thirds of schools (65%) reported having a threat assessment team in place ( NCES, 2024 ). Only 6% of schools used random metal detector checks on students, 2.4% used daily metal detector checks on students, and 3.7% of schools required backpacks to be clear or banned them outright ( NCES, 2024 ; see Table 2-6 ). TABLE 2-6 Percentage of Public K–12 Schools with Various Surveillance Interventions, School Year 2021–2022. The share of schools with surveillance interventions has increased over the last decade. For example, the proportion of schools with an anonymous threat-reporting system has nearly doubled, from 36% in the 2009–2010 school year to 62.4% in 2021–2022. There has been a 30-point increase in the use of security cameras to monitor schools, from 61% in 2009–2010 to 92.6% in 2021–2022 ( NCES, 2011 , 2024a ). Adoption of these systems differs somewhat based on the school's characteristics and the region of the country where it is located. In the 2021–2022 school year, middle and high schools were more likely than elementary schools to have anonymous threat-reporting systems (72.7% of middle schools and 73.3% of high schools, vs. 56.1% of elementary schools) and security cameras (95.9% of middle schools and 96.7% of high schools, vs. 90.7% of elementary schools). Regionally, about three-quarters of schools in the West (81%) reported using security cameras in 2021–2022, compared with other regions, where more than 90% of schools reported using security cameras (Northeast, 96.4%; Midwest, 94.5%; and South, 97.8%). Schools with higher enrollment are more likely than smaller ones to have implemented these surveillance interventions ( NCES, 2024a ). Of the 65% of schools implementing threat assessment teams, schools in cities (71%) and suburbs (69.5%) more often had such a team compared with those in rural areas (53.7%). Threat assessment teams were also more common at the middle and high school levels, at schools with higher enrollment numbers, and at schools with a larger proportion of racial or ethnic minority students ( NCES, 2024a ). The role of surveillance measures in contributing to school safety has a mixed evidence base. Evidence suggests that such interventions may disproportionately affect Black and Hispanic students without reducing the likelihood of exposure to violence ( Lindstrom Johnson et al., 2018 ; Mowen & Parker, 2017 ). For example, Mowen and Parker (2017) , using data from the Education Longitudinal Study, found that the presence of both Black and Hispanic students was associated with a greater overall number of school security measures. In addition, the authors found that secondary schools with higher percentages of Black students were more likely to implement such measures as metal detectors, security personnel, surveillance cameras, designated check-in points, and perimeter fencing, although they did not examine student perspectives on how these measures were experienced. Given that the types and nature of surveillance options have evolved in recent years, this section reviews the current options typically available to and implemented by K–12 schools in the United States. Metal Detectors Schools use metal detectors to identify and deter weapons at entry points. Their use in schools became more common in the 1980s, and by the mid-1990s, approximately one in ten U.S schools had a metal detector. Although slight increases were observed following the school shootings at Columbine High School and Sandy Hook Elementary, their prevalence has remained largely unchanged since the 1990s ( Schildkraut & Grogan, 2019 ). Yet while metal detectors may detect prohibited items, research has not consistently shown that their use leads to a meaningful reduction in serious school violence. Additionally, questions have been raised about the psychological and equity-related impacts of metal detector screening, including the possibility that these measures may contribute to negative perceptions of school climate or be used disproportionately in schools with higher proportions of students of color ( Nance, 2017 ; Schildkraut & Grogan, 2019 ; Schildkraut & Muschert, 2019 ). Security Cameras Security cameras are typically used to monitor school premises and deter potential threats. However, research does not conclusively support their effectiveness in deterring school-based violence. An analysis of national data by Fisher et al. (2021) found that use of security cameras was not associated with reductions in school crime, social disturbances, or exclusionary discipline. A qualitative analysis by Lindstrom Johnson et al. (2018) , using data from 54,350 middle and high school students in Maryland, examined perceptions of school safety in relation to the use of security cameras. The study found that indoor security cameras were associated with lower perceptions of safety, support, and equity. In contrast, moderate use of outdoor cameras was linked to higher perceptions of safety among all students. Black compared with White students reported feeling safer and more supported when outdoor cameras were present; they felt less safe than their White peers in schools with a high number of indoor cameras ( Lindstrom Johnson et al., 2018 ). Across all racial and ethnic groups, as well as among female and younger students, high levels of camera surveillance were associated with a decreased sense of equity in the school environment. Anonymous Threat-Reporting Systems Anonymous threat-reporting systems, including tip lines and mobile apps, have received increased attention as a proactive tool for threat detection. NCES data for 2021–2022 indicate that 62.4 percent of K–12 schools reported using a formal anonymous threat-reporting system (e.g., online submissions, telephone hotlines, and written submission via drop box; NCES, 2022 ). A 2022 randomized controlled trial of more than 700 middle school students in Miami found that schools using an anonymous threat-reporting system experienced fewer violent incidents, particularly when tips were acted upon promptly and effectively ( Hsieh et al., 2022 ). Students were also surveyed on their perceptions of safety, feelings of school connectedness, and feelings of trust in their classmates. Use of a reporting system appeared to prevent declines in these measures that were observed in the schools not using such a system ( Hsieh et al., 2022 ). Other Measures Other measures, such as policies requiring clear backpacks or permitting locker searches, are intended to limit the concealment of weapons or contraband. NCES data for 2021–2022 show that 3.7% of K–12 schools required the use of clear backpacks, and 23.1% conducted contraband sweeps ( NCES, 2022 ). While such practices are sometimes implemented in response to specific threats or incidents, the empirical support for their effectiveness is limited. Some experts have noted negative student perceptions of these practices, as well as concerns about the potential for these measures to stigmatize students or violate their civil liberties ( Addington, 2009 ; Brown, 2005 ; Lesneskie & Block, 2017 ; Moore et al., 2021 ). Behavioral Threat Assessment Some surveillance methods are put in place not to monitor general student behaviors or actions per se, but to serve as tools for evaluating specific individual threats or risks should they arise. Behavioral threat assessment is a structured approach to identifying, assessing, and managing potential threats by evaluating individuals' behavior and risk factors. Behavioral threat assessment practices are currently implemented in an estimated 85% of public schools across the United States ( NASEM, 2024 ), and like many safety and security measures, their implementation varies widely across schools and states. Some states use tiered or multidisciplinary models ( Kim et al., 2021 ), while others provide standardized toolkits, and still others provide only general guidelines for implementation. This inconsistency in implementation often results from a variety of factors, including differences in local laws, school and district-level resources, and individual school and student needs, leading to uneven application of threat assessment procedures. However, behavioral threat assessment in its various forms is a tool that, when implemented as intended, has a strong evidence base for its effectiveness and as part of a broader school safety framework ( Rajan et al., 2022 ). The use of evidence-based behavioral threat assessment practices is critical if this tool is to be effective in preventing violence and managing potential threats ( Cornell & Maeng, 2018 ), and for making sure that interventions are fair and do not cause breakdowns in trust within the school system, and to ensure that students are well supported even in—one might argue especially in—moments of crisis. Examples of well-established behavioral threat assessment processes include the Comprehensive School Threat Assessment Guidelines, which have been shown to improve safety outcomes and reduce bias ( Cornell, 2018 ). In addition, and to better support school systems, several organizations and agencies offer resources to guide schools in implementing the process. For example, NASP (2021a) has synthesized the existing literature to provide a detailed framework for K–12 schools, including how to establish a multidisciplinary team, how to implement a structured referral process, best practices for communication, and even ongoing professional development resources. Similarly, several states (e.g., school safety efforts in North Carolina and Texas) have provided tailored guidelines for schools that are driven by the existing evidence and readily accessible. Resources such as these are examples of resources that can help K–12 schools align their practices with proven methods, increasing both efficacy and equity in managing potential threats. Mental Health First Aid Mental health first aid training programs can complement behavioral threat assessment by helping individuals identify and assist those experiencing mental health issues. Research indicates that such training can improve the ability of school staff to support students and respond to mental health crises ( Gryglewicz et al., 2018 ; Jorm et al., 2010 ; Sanchez et al., 2020 ). Personnel Interventions and Training In general, there are three broad categories of school security personnel ( Fisher et al., 2023 ; James & McCallion, 2013 ; NASRO, n.d. ). First are school resource officers (SROs)—sworn law enforcement officers who have received training and are certified specifically for working within a school. Second, some school districts may use non-SRO law enforcement officers. These officers are sworn law enforcement but have not received SRO training. Box 2-2 describes school resources officers in more detail. Third, non–law enforcement school security personnel have not received training or special certification to work within schools. In the face of recent reported shortages of SROs and other law enforcement officers who can be assigned to schools ( Fisher et al., 2023 ; Turanovic et al., 2022 ; Woulfin & Sadler, 2023 ), however, some schools have come to rely solely on non–law enforcement security personnel. BOX 2-1 School Resource Officers. According to the SSOCS, 60.6% of public K–12 schools had one or more security staff member 13 present at the school at least once a week in 2021–2022, up from 43% in 2013–2014 ( NCES, 2024a ). In about half of schools (44.8%) in the 2021–2022 school year, the security staff included at least one sworn law enforcement officer who routinely carried a firearm. In the 2009–2010 school year, 28% of public schools reported having any security staff member 14 who routinely carried a firearm ( NCES, 2011 ; see Figure 2-2 shows these trends). FIGURE 2-2 Trends in percentage of U.S. public K–12 schools with security staff and law enforcement personnel, school years 2005–2006 to 2021–2022. NOTE: Security staff include security guards/officers, security personnel, school resource (more...) The presence of security staff varies somewhat based on certain school characteristics. For instance, security staff are more common at larger schools: schools with 1,000 or more students reported having one or more school resource officer (74.4%), other sworn law enforcement personnel (12.1%), or security officers or security personnel (54.9%) in 2021–2022, compared with schools with fewer than 300 students, which reported having school resource officers (31.5%), other sworn law enforcement personnel (11.6%), or security officers or security personnel (15.7%) ( NCES, 2024a ). More than 60% of middle (62%) and high (62.4%) schools had school resource officers present at least once a week during the 2021–2022 school year, compared with 33% of elementary schools ( NCES, 2024a ; see Table 2-7 ). TABLE 2-7 Percentage of Public K–12 Schools with One or More Full- or Part-time Security Staff Present at Least Once a Week, School Year 2021–2022. School resource officers and/or law enforcement personnel may be assigned to schools specifically to provide security and build relationships with students. Existing research focusing on their effects on students, staff, and school climate is limited and has yielded mixed results (e.g., Crichlow-Ball et al., 2022 ; Flannery et al., 2021 ; Sorensen et al., 2023 ). The presence of school security staff (both law enforcement and non–law enforcement) may affect various groups of students differently. For example, school resource officers may enhance feelings of safety for some students ( Theriot & Orme, 2014 ), but they may also be associated with higher rates of exclusionary discipline, which impacts students of color disproportionately ( Fisher & Hennessy, 2016 ). School districts sometimes use non–law enforcement security personnel who are trained to handle security issues in schools to contribute to increased safety and greater opportunities for surveillance, interventions in the moment, and relationship building. These personnel have been associated with lower rates of student arrest and exclusionary discipline, although their efficacy at deterring firearm violence in particular is not known ( Vernon & Curran, 2023 ). 15 Finally, it bears noting that policies at the school district level and in more than 30 states allow teacher to carry firearms as a means of defending against threats. There is currently no evidence that arming teachers is effective at deterring firearm violence nor reducing the lethality of a shooting should one occur ( Smart et al., 2024 ). 16 A synthesis of existing research on gun policies in the United States found no qualifying studies showing a benefit from arming teachers as a way of reducing firearm violence in schools; the authors noted concerns among school safety experts related to the potential risks of introducing more firearms into school environments ( Smart et al., 2024 ). EXPOSURE TO SCHOOL ACTIVE SHOOTER DRILLS AND SECURITY MEASURES Previous sections of this chapter highlight potential differences in how students and school staff are exposed to school active shooter drills, hardening and surveillance measures, and the presence of law enforcement officers and other security personnel. Certain school security measures have higher visibility than others. Although literature on crime prevention through environmental design —an approach for reducing crime though strategic management of the physical environment—emphasizes designing for both safety and positive social interaction, some school security measures, such as visible security cameras, fences, and the presence of armed personnel can signal safety concerns or heighten the sense of surveillance ( Lamoreaux & Sulkowski, 2019 ; Lindstrom Johnson et al., 2018 ). Current data highlight differential exposures to school security measures, particularly along racial and ethnic lines ( Cuellar & Coyle, 2020 ; Mowen & Parker, 2017 ; Payne & Welch, 2023 ). By contrast, data are more limited on variations in exposure of students' and staff exposure to school active shooter drills—particularly regarding the specific practices and approaches that are encompassed by this broad category. Given that active shooter drills are widely implemented in U.S. schools, it is more likely that students will differ in the types of drills they experience than in whether they experience them at all. Geographical differences also matter, as urban, suburban, and rural residence, along with state or regional requirements, can influence the types and frequency of safety measures implemented. For example, variation in state requirements for active shooter drills—as noted in Table 2-1 —range from zero to four or more mandated drills per year, resulting over time in large differences in student exposure to drills. To date, there has been little research on the cumulative effects of exposure to multiple school active shooter drills and other school security measures, despite the potential for various safety measures to act collectively to shape student perceptions and behaviors, either positively or negatively ( Lindstrom Johnson et al., 2018 ; Mowen & Freng, 2018 ; Perumean-Chaney & Sutton, 2013 ). As researchers and practitioners gain a deeper understanding of individual approaches, they need to consider the interaction among different strategies and whether exposure to multiple strategies could amplify adverse effects. For example, school active shooter drills led by law enforcement personnel might be more concerning for students relative to those facilitated by school staff or mental health professionals. The fact that school safety and security strategies vary and may be implemented in combination (discussed further in Chapter 4 ) raises questions about whether specific strategies interact positively or negatively, and about how individual strategies may affect mental, emotional, and behavioral health outcomes. When research designs examine more than one school safety strategy simultaneously, the results are typically conflated, making it difficult to determine the effects of each on school safety and school climate overall. Such a research approach leads to a situation in which either all strategies are deemed to work, or none. Thus, more studies are needed to investigate whether individual strategies complement each other, affect the well-being of students and staff positively or negatively, improve school safety, or potentially counteract one another. It is also crucial to determine whether certain groups of strategies are more effective than others. Chapter 7 provides the committee's detailed agenda for future research on these and related topics. CONCLUSION The landscape of school safety in the United States is shaped by a broad array of strategies, including school active shooter drills, other security measures, and broader efforts to foster a positive school climate. These components, while often implemented together, vary considerably across states, communities, and individual schools, reflecting differences in available resources, regional policies, and local priorities. A comprehensive approach to school safety integrates practices that support the mental, emotional, and behavioral health of students and staff with emergency preparedness practices and security measures. Despite the widespread adoption of school active shooter drills and other security measures, the evidence base on their effectiveness remains fragmented. Existing research often combines individual measures without examining their interactive effects, limiting understanding of whether specific strategies complement or counteract one another. This gap in the literature underscores the need for more rigorous, holistic research that evaluates school safety strategies not only in isolation but also in combination, particularly in how they shape student and staff perceptions of safety, preparedness, and well-being. Furthermore, gaps in resources and access to supportive interventions pose critical challenges, particularly for under-resourced schools. Schools with limited funding, for example, are less likely to have access to essential health professionals, such as school counselors, school psychologists, school social workers, and school nurses, despite evidence indicating that these supports play an important role in promoting student resilience, social-emotional skills, and prosocial behavior. Trauma-informed practices, which recognize and respond to the effects of trauma on student behavior and learning, represent another important component of a holistic school safety strategy. Without access to these supports, schools may be left with a reactive rather than a preventive approach, focusing narrowly on security measures instead of addressing the root causes of violence and behavioral challenges. As the committee has emphasized, the available evidence shows that a balanced and evidence-informed school safety strategy needs to extend beyond immediate crisis preparedness to encompass long-term efforts that cultivate a secure, inclusive, and supportive learning environment, one that fosters resilience and well-being. 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School Mental Health. 2022; 15 :1–18. https://doi ​.org/10.1007 ​/s12310-022-09535-0 . [ PMC free article : PMC9321305 ] [ PubMed : 35911088 ] Footnotes 10 For the purposes of this report, the committee uses the term standard response practices to refer to individual, predefined actions or procedures designed to guide students and staff in responding to different types of emergency situations, including school active shooter events. 11 Buffer zones are areas intended to create separation between the school and a potential threat; they may include other security elements such as fencing, gates, or controlled access points. 12 A hard corner is a designated safe area in a classroom where occupants can seek refuge away from doors and windows in the event of an emergency. 13 Security staff include security guards/officers, security personnel, school resource officers, and sworn law enforcement officers who are not school resource officers. Security guards/officers and security personnel do not include law enforcement personnel. School resource officers include all career law enforcement officers with arrest authority who have specialized training and are assigned to work in collaboration with school organizations. 14 Prior to 2015–2016, the SSOCS questionnaire asked respondents whether any of the security guards, security personnel, or sworn law enforcement officers at their school routinely carried a firearm. In 2015–2016 and later years, the SSOCS questionnaire asked respondents only whether any of the sworn law enforcement officers (including school resource officers) at their school routinely carried a firearm. While data across years are not directly comparable because of these changes in categorization, they illustrate a broader trend of growth in the proportion of schools with security staff who routinely carry a firearm. 15 Vernon and Curran (2023) 's epidemiological analysis using representative data from the Civil Rights Data Collection found that use of non-sworn security personnel may minimize the student arrests and use of exclusionary discipline. 16 Smart and colleagues (2024) conducted a systematic review of scientific evidence on laws related to allowing for K–12 staff to carry a firearm or associated outcomes. No studies met the authors' inclusion criteria related to the impact of such laws on outcomes such as mass shootings, violent, crimes, or unintended injury. The authors also note that there exists no comprehensive accounting of the extent to which school districts allow teachers or other school personnel to carry a firearm. Copyright 2025 by the National Academy of Sciences. National Academies of Sciences, Engineering, and Medicine and National Academies Press and the graphical logos for each are all trademarks of the National Academy of Sciences. All rights reserved. Bookshelf ID: NBK619269 Contents < Prev Next > Share Views PubReader Print View Cite this Page National Academies of Sciences, Engineering, and Medicine; Division of Behavioral and Social Sciences and Education; Committee on Law and Justice; Board on Children, Youth, and Families; Committee on the Impact of Active Shooter Drills on Student Health and Wellbeing; Hutton R, Bonnie RJ, editors. School Active Shooter Drills: Mitigating Risks to Mental, Emotional, and Behavioral Health. Washington (DC): National Academies Press (US); 2025 Oct 17. 2, The Landscape of School Active Shooter Drills and Other School Security Measures. PDF version of this title (6.9M) In this Page CONTEXT OF SCHOOL SAFETY THE LANDSCAPE OF ACTIVE SHOOTER DRILLS LANDSCAPE OF OTHER SCHOOL SECURITY MEASURES EXPOSURE TO SCHOOL ACTIVE SHOOTER DRILLS AND SECURITY MEASURES CONCLUSION REFERENCES Related information PMC PubMed Central citations PubMed Links to PubMed Recent Activity Clear Turn Off Turn On The Landscape of School Active Shooter Drills and Other School Security Measures... The Landscape of School Active Shooter Drills and Other School Security Measures - School Active Shooter Drills Your browsing activity is empty. Activity recording is turned off. Turn recording back on See more... Follow NCBI Twitter Facebook LinkedIn GitHub NCBI Insights Blog Connect with NLM Twitter Facebook Youtube National Library of Medicine 8600 Rockville Pike Bethesda, MD 20894 Web Policies FOIA HHS Vulnerability Disclosure Help Accessibility Careers NLM NIH HHS USA.gov