4
Mental, Emotional, and Behavioral Health Effects of Selected School Security Measures

The committee’s charge, as reflected in its statement of task (Box 1-1 in Chapter 1), focuses on the short- and long-term effects of school security measures, particularly those relating to the implementation of active shooter drills. As examples of other security measures of interest, the statement of task mentions metal detectors and police presence; the committee included both security measures in this study. It expanded the category of “police presence” to include school security staff more broadly, including school resource officers (SROs), other sworn law enforcement officers, and non–law enforcement security staff. The committee also included door locks as a security measure of interest because of their widespread use, both generally and specifically in lockdown procedures that are part of some active shooter drills. This chapter focuses on these measures and their potential effects on mental, emotional, and behavioral health.

The relationship between common school security measures and the implementation of active shooter drills is complex, reflecting broader debates about school safety and preparedness. These measures may interact with drills or each other in ways that can either reinforce or complicate the intended objectives of emergency preparedness, school security, and student well-being. Using these measures can influence the outcomes of the drills, as well as the overall school environment and school safety climate (Langhout &

Annear, 2011; Mowen & Freng, 2019; Schildkraut & Nickerson, 2022).

It is important to keep in mind the complexity of assessing the impact of school security measures, recognizing that these interventions are inherently shaped by school climate. In other words, their impact cannot be fully understood in isolation from the relational, social, and cultural dynamics of the school environment.

This chapter provides an overview of the nature, scope, and quality of the empirical evidence bearing on the impact of school security measures—specifically, locked doors, metal detectors, and school-based security personnel—on the mental, emotional, and behavioral health outcomes of K–12 students and staff. The discussion builds on the previous chapters by synthesizing existing research on school security measures currently used in U.S. public schools, with a specific focus on measures that may be implemented as part of school safety strategies or play a role in the implementation of school active shooter drills in particular. The chapter summarizes the available research literature pertaining to each of the above security measures and their relationship to the mental, emotional, and behavioral health outcomes of interest—specifically perceived emergency preparedness or knowledge, perceptions of safety or fear, student trauma and mental health concerns, student perceptions of school connectedness, school violence, and student behavior. The committee specifically includes school connectedness—students’ feelings of being cared for, valued, supported, and having a sense of belonging—as an outcome of interest because research indicates that students who feel connected to their school community are less likely to experience poor mental health and are more likely to experience long-term benefits for overall health and well-being (Steiner et al., 2019; U.S. Centers for Disease Control and Prevention, 2023). Moreover, connectedness is a foundational element of a safe and supportive school environment. (Recall that the committee’s conceptual framework, presented in Chapter 1, identifies a positive school climate as a critical protective factor shaping the outcomes of interest.)

Studies related to school climate are included, where relevant, to further contextualize the committee’s findings. As noted in Chapter 3, this report does not take up the question of security effectiveness; it focuses solely on mental, emotional, and behavioral health outcomes for students and staff. School policymakers will need to weigh the potential harms associated with use of these measures against their possible benefits, taking into account their specific context and circumstances.

ADVANTAGES AND LIMITATIONS OF RESEARCH DESIGNS

Empirical research related to school security measures varies in design, scope, and methodological rigor. Studies span numerous disciplines including education, psychology, public policy, sociology, and criminology. There is a growing body of research on the effectiveness of school security interventions; however, like the evidence bearing the impact of school active shooter drills, the evidence on the effects of school security measures is characterized by several key limitations and gaps in methodological rigor.

The literature reviewed by the committee for this chapter fell into five primary categories: quasi-experimental studies, cross-sectional studies, longitudinal studies, systematic and integrated reviews, and qualitative studies (see Table 4-1). In the context of understanding the effects of school security measures on mental, emotional, and behavioral health outcomes, each of these methodological approaches offers distinct advantages and limitations in assessing both the short- and long-term effects on students and staff. In general, even when a correlation emerged, most studies did not establish causality because of the reliance on observational designs, which made it difficult to isolate the effects of security measures from other factors that could lead to similar outcomes. Variability in the implementation of security measures across schools further complicates comparisons and limits the extent to which effects can be generalized. Unfortunately, very few longitudinal studies are

available to help understand and isolate the long-term effects of school security measures. Finally, some school security measures may have unintended negative effects such as increased anxiety, but these effects are not measured consistently across studies.

The following sections further describe the strengths and limitations of the above five research types in assessing the effects of school security measures on the committee’s key outcomes of interest—while keeping in mind the complexity of student and staff experiences and the resulting difficulty of isolating specific effects.

Quasi-Experimental Studies

Quasi-experimental studies provide stronger causal evidence than is possible with purely observational studies. They allow for retrospective analysis using existing datasets, which can be more practical than randomized controlled trials for evaluating the effects of school security measures. However, these studies often focus on interventions with limited contexts, which can reduce their generalizability. They may also be vulnerable to unmeasured confounding factors.

Quasi-experimental studies could be used to assess impacts in a variety of ways. For example, pre- and postintervention data could be used to evaluate whether or not increased security presence enhances perceptions of safety or whether it fosters or hinders students’ sense of belonging as compared with matched school environments. These studies may also highlight unintended mental, emotional, and behavioral health consequences by tracking anxiety levels and trauma-related symptoms before and after security measures are instituted. Because they often rely on secondary data sources, however, they may not be able to capture impact fully.

Cross-Sectional Studies

Most of the studies reviewed by the committee were cross-sectional in design, highlighting a significant gap in the longitudinal and experimental research necessary for establishing causal relationships. Cross-sectional studies provide a snapshot of the current

school security landscape and immediate effects of security measures; they can be both cost-effective and time efficient.

Despite these strengths, they have limited ability to establish causality because they collect data only at one point in time and thus cannot account for some of the changes in outcomes over time that have been observed for some school security measures. Cross-sectional data can highlight variations in outcomes resulting from implementing security measures over time but cannot capture changes in outcomes such as perceived connectedness. These short-term findings may also not reflect long-term outcomes. And while associations between security measures and outcomes can be explored with a cross-sectional design, it is unclear without preintervention data whether these measures contribute to or mitigate mental, emotional, behavioral health effects. Cross-sectional studies are also unable to disentangle whether changes in student behavior result from security interventions or other school climate factors.

Longitudinal Studies

The committee found just two longitudinal studies, and only one related specifically to security measures of interest to the committee (Fisher et al., 2018). The other related to school safety and its effects on participation in school activities (Mowen & Manierre, 2017).

Longitudinal studies could provide valuable insights into how the implementation of various school security measures impacts students and staff over extended periods of time by identifying trends, delayed effects, and developmental consequences. With respect to the committee’s outcomes of interest, longitudinal studies could be used to assess whether initial changes in perception of safety after a security intervention persist or change over time, whether there are delayed consequences as a result of prolonged exposure to security measures, whether there are long-term effects on perceptions of belonging and school social cohesion, and whether there are behavioral trends (e.g., in absenteeism, engagement, or disciplinary referrals) that can be linked to school security measures.

Conducting this kind of research on the effects of school security measures present many challenges. For example, outcomes can be affected by changes in school policies and security measures over time, attrition of students and staff, lack of sustained funding, significant time investments, and the need for data to make real-time policy decisions.

Systematic and Integrated Reviews

Given the limited longitudinal data on the effects of school security measures on the mental, emotional, and behavioral health of students and staff, systematic and integrated reviews provide a way to synthesize findings across available studies to assess the overall body of evidence on these measures. The committee identified five such studies. In addition to providing insight into the gaps in the existing evidence base, systematic and integrated reviews can identify patterns in research findings on the effects of security measures (e.g., anxiety or desensitization), clarify whether these measures undermine students’ and school staff’s sense of safety, provide insights into the relationship between the measures and school climate, and assess which interventions are associated with improvements or declines in mental, emotional, behavioral health across different school contexts.

However, the strength of the findings emerging from such reviews depends on the rigor of the studies they can include. Because of the variability in study designs, outcome measures, interventions, and school and student contexts addressed in the included studies, the comparability of findings may be limited, and the conclusions that can be drawn from those findings may be correspondingly weak.

Qualitative Studies

The committee reviewed five qualitative studies: four focused on school safety and security broadly and one focused on school security staff specifically.

Although few qualitative studies on this topic were found, they have the potential to provide rich, in-depth insights into the experiences of students and school staff and to capture nuances at the school level that could be overlooked in quantitative studies—in particular, unintended consequences and social and contextual dimensions of school safety and security policies. For example, qualitative studies can reveal insights that go beyond statistical outcomes and capture population-specific perspectives—such as why some school security measures may foster reassurance, while others may heighten fear, or how and why a measure may affect relationships between students and staff.

The challenge of qualitative research designs, however, is that their findings can lack generalizability to larger populations, and the studies are not designed to establish causal relationships or quantify the effects of school security measures.

TABLE 4-1 Studies About the Effects of School Security Measures (Other than Active Shooter Drills)

CHARACTERISTICS AND LIMITATIONS OF THE EXISTING EVIDENCE BASE

While existing research provides some insights into the impacts of school security measures, the overall evidence base remains limited in both rigor and generalizability. Each research design contributes valuable insights into the relationship between school security measures and preparedness, perceptions of safety, mental health, school connectedness, and student behavior. However, significant gaps remain, particularly in causal inference and long-term impact assessment. The predominance of cross-sectional studies limits the ability to draw definitive conclusions, while the scarcity of longitudinal and quasi-experimental research constrains understanding of sustained effects. Systematic reviews provide overarching insights, yet their conclusions depend on the quality of the underlying studies. Qualitative research offers depth and context but lacks generalizability. Strengthening research designs will be critical for informing and developing policies aimed at implementing school security measures while mitigating potential harm to the mental, emotional, and behavioral health of students and staff.

Taking account of the nature and quality of the existing evidence, this section examines key patterns of policy and practice in school security bearing on the mental, emotional, and behavioral health of students and staff. Overall, very few studies feature designs rigorous enough to isolate the influence of security measures on student behavioral and emotional outcomes

Three decades of research has explored the use of door locks, metal detectors, and school-based security personnel in schools. Most of this literature relies on analysis of one of four datasets: the School Survey on Crime and Safety (SSOCS); the School Crime Supplement to the National Crime Victimization Survey (SCS); the National Longitudinal Study of Adolescent to Adult Health (Add Health); and the Education Longitudinal Study of 2002. While

SSOCS and the SCS are cross-sectional datasets, the other two are, as their names suggest, longitudinal.

Few studies of metal detectors or school-based security personnel have featured experimental designs, and the committee identified only four quasi-experimental studies related to these security measures and their potential effects on mental, emotional, or behavioral health of students or staff. In addition, research methods used in these studies rarely disentangle the aim of preventing school violence through use of metal detectors from other potential outcomes such as increasing students’ sense of safety. The studies reviewed by the committee also lack consistent measures of mental, emotional, and behavioral health outcomes, leading to difficulties in interpreting findings and assessment of causation. For example, Fisher et al. (2019) discussed a number of studies that found that more schools have begun to incorporate formal security measures (e.g., metal detectors, security personnel, surveillance cameras) and examined the effects of these measures on reducing problem behaviors (e.g., bullying, victimization, fighting, drug or alcohol use) among students. However, the literature Fisher et al. (2019) reviewed did not consistently define or measure the same types of behaviors, making it difficult to identify clear patterns of outcomes for specific behavioral issues.

Despite these limitations, the cumulative evidence suggests that school security measures can have different psychological and social consequences that may vary by school contexts. For example, Cobbina et al. (2019) conducted a qualitative study on schools in Flint, Michigan; they interviewed students in grades 7–12 and found that, a large proportion of the students they interviewed reported that the presence of physical security measures made them feel more safe. This contrasts with some studies showing the use of physical security measures to be associated with a decrease in perception of safety. Cobbina et al. (2019) noted that the unique characteristics of both the community, which had high rates of crime, and the school system, which had experienced numerous school closures and a decrease in student population, make it difficult to generalize these findings.

In their qualitative study, Perumean-Chaney & Sutton (2013) found that an increase in the number of security measures was generally associated with a decrease in students’ perceptions of safety; however, this was not true for all students in their study. Students who were White, male, had a higher GPA, and felt safe in their neighborhood were more likely to feel safe at school than other groups of students. They also found that school safety was more strongly predicted by individual- and school-level factors than by the presence of security measures (Perumean-Chaney & Sutton, 2013). Taken together, these findings exemplify the need to consider supports and strategies for meeting the needs of individuals and school communities (Cobbina et al., 2019; Perumean-Chaney & Sutton, 2013).

Research has often explored security measures as broad categories, rarely accounting for nuances in how those measures were utilized or for variations in responses to different security measures. For example, most schools rely on one of two types of metal detectors—handheld wands, which are generally used for spot checks or targeted searches, or stationary/walk-through metal detectors, which are generally used at controlled entry points to the school or as part of metal detector checks (Gastic & Johnson, 2015; Schildkraut & Grogan, 2019). However, the committee did not find any studies that specifically discussed the differences in how the potential mental, emotional, and behavioral health effects on students and staff vary by type, frequency of use, or manner of implementation.

Research that accounts for contextual factors such as school demographics, socioeconomic status, and the level of enforcement finds that the same security measures can have divergent effects. For instance, metal detectors implemented in schools with a history of violence, or in communities with higher rates of crime, may be perceived differently from those installed in schools where safety concerns have been minimal, where they may contribute to a sense of excessive surveillance among students (Bhatt & Davis, 2018; Cobbina et al., 2019; Nguyen et al., 2020). This variability suggests that the impact of security measures is not uniform, and that implementation strategies must be carefully considered with attention to

school and student contexts to avoid unintended negative mental, emotional, and behavioral health outcomes.

Few studies have explored how one type of security measure may influence how students experience other types of security measures that are in use within a school. One theme that emerged in the committee’s review of the research literature is the potential for student outcomes to vary based on the number or combination of visible security measures present within a school (e.g., Tanner-Smith et al., 2018). This is particularly relevant given findings in existing literature that show that the cumulative effect of multiple security measures may be to lower perceptions of safety or amplify student distrust, particularly when those measures are perceived as invasive or disproportionately enforced against certain demographic groups (Kupchik & Farina, 2016; Mowen & Freng, 2019). Thus, security measures need to be evaluated holistically, taking into account the ways in which various measures interact to shape student and staff experiences.

Understanding these contextual influences is critical in evaluating whether security measures achieve their intended goals, as well as the ways in which they may contribute to unintended negative consequences. School climate also plays a crucial role. Bosworth et al. (2011) found that strong relationships between students and teachers, and a sense of school connectedness, play a key role in creating a safe and protective school environment that can foster a sense of safety.

To summarize, while the studies reviewed by the committee provide valuable insights, many rely on student self-reports rather than psychological assessments or analyses of longitudinal data, meaning that the long-term mental, emotional, and behavioral health outcomes, and the ways that outcomes may change over time, remain essentially unexplored. Additionally, individual- and school-level characteristics are often explored without fully disentangling other intersecting factors, such as socioeconomic background and other demographic characteristics, community context, urbanicity, and student developmental needs, which may also play a role in shaping these perceptions.

REVIEW OF EVIDENCE ON PHYSICAL SECURITY INTERVENTIONS

Physical security measures such as door locks have become standard features in many educational institutions. According to the National Center for Education Statistics (Musu et al., 2019), nearly 94% of public K–12 schools in the United States report locking or monitoring their doors during school hours as a security measure. These strategies are designed to reduce or impede potential threats and restrict unauthorized access, particularly in the wake of high-profile school shootings. Locking of school and classroom doors is a practice that is often integrated into school active shooter drill practices. However, the committee did not find any studies that were specifically focused on the effects of door locks—in particular—on mental, emotional, and behavioral outcomes. The committee found only one which focused on door locks as a security measure, which was focused on ease of use. Martaindale et al. (2023) note that while classroom door locks can be a key deterrent to intruders attempting to enter classrooms and no shooter has breached a locked door, the design and ease of use of door locks can affect how quickly and easily they can be used when individuals are under stress. However, the broader impact of door locks remain largely unexamined in the current research literature, representing a significant gap in the evidence base related to their potential mental, emotional, and behavioral health effects on students and staff.

With this important gap in mind, this section examines existing evidence on how door locks may influence students’ psychological well-being, emotional security, and behavioral responses, considering these measures’ protective benefits as well as potential unintended consequences. Given the limited evidence specific to this security measure, the review includes studies on school security measures that included, but were not limited to, findings related to door locks.

Perceived Emergency Preparedness or Knowledge

The available research reviewed by the committee provides limited but relevant insights into the impact of door locks as a school security measure and their relationship to students’ perceptions of preparedness for emergencies.

While several studies have included the presence of door locks as part of broader school security measures, Martaindale et al. (2023) is the only study the committee found that was focused specifically on their use. Their randomized controlled trial evaluated differences in ease of use between two types of classroom door locks used to secure a classroom as part of a lockdown. The study found that push-button locks are easier to use than locks that require a key when individuals are under stress (Martaindale et al., 2023). While evaluating the effectiveness of lockdowns was outside the committee’s scope, the inclusion of lockdown procedures in some active shooter drills led the committee to view the ability to implement them as a possible contributor to a sense of preparedness. Further research examining whether students and staff feel more prepared when they are confident in their ability to successfully perform lockdown procedures—or when specific types of locks are used—would provide valuable insights.

The available evidence does not examine whether door locks alone contribute to students feeling more prepared for emergencies. As reviewed in the previous chapter, Schildkraut & Nickerson (2022) found that lockdown drills—which often involve door-locking procedures—were associated with reduced fear and improved perceived preparedness among students. The very act of practicing could be a key aspect of creating this sense of preparedness (rather than the physical presence of the door locks alone), but the available evidence does not disentangle these factors.

In summary, existing research primarily assesses physical security outcomes rather than perceptions of preparedness, leaving a gap in understanding how door locks influence mental, emotional, and behavioral health outcomes for students and staff. As a result, their role in fostering a sense of preparedness remains unclear.

Perception of Safety or Fear

A major impediment in interpreting the studies reviewed by the committee is the difficulty of isolating the effects of door locks from the effects of other security measures such as surveillance cameras, school resource officers or other security staff, and metal detectors. Several studies on school security measures that included discussion of door locks—though not exclusively focused on door locks—provide some indirect insights into perceptions of safety or fear. Mowen & Freng (2019) examined how various security measures (e.g., metal detectors, security guards, security cameras), including locked doors, influence feelings of safety among students and parents. Their findings were mixed, suggesting that multiple security measures did not increase perceptions of safety for either students or parents (Mowen & Freng, 2019). Similarly, in a cross-sectional study of the effects of school security measures on preventing bullying and victimization among students aged 12–18 in U.S. schools, Gerlinger & Wo (2016) reported that that while locked doors and other security measures (e.g., guards, metal detectors) have been shown to increase feelings of physical safety in some cases, evidence has not definitively demonstrated that these measures alleviate students’ fear of victimization. By contrast, Cobbina et al. (2019) studied students in grades 7–12 in a school district with high rates of crime; they found that some students felt safer when school and classroom doors could be locked. However, the authors note that the unique school and community contexts of the students in their qualitative study makes it difficult to generalize the findings to broader student populations (Cobbina et al., 2019).

It is important to emphasize that most research on school security evaluates multiple interventions simultaneously, making it challenging to identify the specific impact of door locks on perceptions of safety or fear. Thus, further investigation is needed into the mental, emotional, and behavioral health effects of the use of door locks specifically, rather than school security measures in general.

Student Trauma and Mental Health Concerns

The committee did not identify any research explicitly connecting the use or presence of door locks with outcomes related to trauma or mental health. Studies mentioning these outcomes were focused on school security measures broadly—including door locks—but did not definitively link psychological impact to individual physical security interventions.

Student Perceptions of School Connectedness

The committee found no direct evidence bearing on the effect of door locks on perceptions of school connectedness. Again, most studies evaluated multiple security measures together, making it difficult to determine the individual impact of door locks. Studies pertaining to the effect of high-security environments, which can decrease students’ sense of belonging and decrease trust between students and staff, may provide some indirect insight (e.g., Mowen & Freng, 2019; Tanner-Smith et al., 2018). Research focused on door locks is needed to understand what effect they may have on school connectedness.

Student Behavior

No studies appear to have linked the simple presence or use of door locks to changes in student behavior. Discussions of behavior changes have typically been part of broader discussions of security measures, including door locks or lockdown procedures (e.g., Schildkraut & Nickerson, 2022).

REVIEW OF EVIDENCE ON METAL DETECTORS

The use of metal detectors in U.S. schools tends to vary by school level and urbanicity, but they are relatively uncommon—present in roughly 1 in 10 schools—and their prevalence has remained largely unchanged since the mid-1990s; they are more common in

urban schools and are used more frequently in secondary than in elementary schools (Addington, 2018; Schildkraut & Grogan, 2019). The intended goal is to deter students from bringing contraband items to school and to create a safe environment where both students and staff feel secure (Brown, 2005; Tanner-Smith et al., 2018).

The literature on school security measures generally does not distinguish between the influence of metal detectors and the influence of security personnel. One study found that, in an analysis of two separate datasets, spanning 2001–2011 and 2004–2010, the use of metal detectors nearly always coincided with schools’ use of security cameras and security personnel (Tanner-Smith & Fisher, 2016). Multiple studies examined school security as a composite variable—that is, they used a single measure to capture how many different types of security measures schools had in place—no studies identified by the committee explicitly compared the effects of metal detectors alone with their use in combination with security personnel or other security measures. Thus, there is a notable gap in direct comparative research between singular and combined approaches.

Early analyses focused on the impact of metal detectors on school safety—particularly on carrying weapons and school violence—seeking to determine the extent to which metal detectors have fulfilled their primary objective (Bhatt & Davis, 2018; Hankin et al., 2011; Tanner-Smith et al., 2018). However, much of the research over the past 2 decades has explored the implications of metal detectors for student perceptions of safety—generally finding that students may feel less safe if they are in schools with metal detectors (Gastic, 2011; Perumean-Chaney & Sutton, 2013). However, there is little research focused on other student outcomes of interest (e.g., perceived emergency preparedness, trauma, or other adverse mental health effects). This section summarizes the available findings on the use of metal detectors as they relate to the committee’s interest in mental, emotional, and behavioral outcomes.

Perceived Emergency Preparedness or Knowledge

The committee was unable to identify any studies examining the connection between metal detectors and student perceptions of their preparedness for an emergency or their knowledge of how to respond in an emergency.

Perceptions of Safety or Fear

The committee identified several studies that either focused specifically on metal detectors or included them among the school security measures examined; these studies generally explored associations with perceptions of safety or fear. Studies measure student fear in multiple ways, including fear at school (Bachman et al., 2011a; Tillyer et al., 2011), fear going to and from school (Bachman et al., 2011b), sense of safety at school (Addington, 2018; Cuellar et al., 2017; Gastic, 2011; Mowen & Freng, 2019; Perumean-Chaney & Sutton, 2013), perceived neighborhood safety (Fisher et al., 2018), and school avoidance due to fear (Bhatt & Davis, 2018).

Among the studies examining perceptions of safety or fear, the most useful are two quasi-experimental studies; as mentioned above, both found that students in schools with metal detectors felt less safe than their counterparts in schools without metal detectors (Gastic, 2011; Perumean-Chaney & Sutton, 2013). These findings are largely consistent with the significant body of studies exploring other dimensions of student fear and sense of safety. Gastic’s (2011) study using data from Add Health found that use of metal detectors in schools had a negative impact on students’ perception of safety; however negative associations between sense of safety and the use of metal detectors were 13% less among students in urban schools relative to students in suburban or rural schools. Gastic (2011) emphasized the need for interventions that not only reduce risk to students but also promote their sense of safety. Perumean-Chaney & Sutton’s (2013) study on the impact of school safety measures on students’ perceptions of safety also used Add Health data with a nationally representative sample of 13,386 students in grades 7–12 in

130 schools. They found that the use of metal detectors in schools was associated with students having concerns about their safety and that, among the security measures examined, metal detectors may be particularly associated with reduced perceptions of safety (Perumean-Chaney & Sutton, 2013).

A cross-sectional study by Tillyer et al. (2011) examined the effects of crime prevention efforts on students’ perception of risk and fear of crime. In their examination of five crime prevention measures (school efficacy, police involvement in the school, presence of metal detectors, locker checks, and bans on book bags/backpacks) they found that only metal detectors were related to lower levels of fear among students, although metal detectors were not found to be associated with lower levels of violence.

The majority of relevant studies reviewed by the committee relied on cross-sectional, self-reported data, making it difficult to determine whether metal detectors cause changes in perceived safety or are simply implemented in response to preexisting concerns (Hankin et al., 2011). Furthermore, the existing evidence base lacks controlled experimental research that isolates the effects of metal detectors from those of other security measures. As a result, while metal detectors are intended to improve school security, their actual impact on perceptions of safety and fear appears to be negative and context dependent.

Student Trauma and Mental Health Concerns

Beyond the research examining the potential impacts on student fear, there have been no studies examining the implications of metal detectors for student trauma and mental health. Given the nature of the evidence, which is based primarily on self-reported perceptions rather than clinical assessments, the committee was unable to draw any conclusions about the effects of metal detectors on student trauma and mental health.

Student Perception of School Connectedness

As noted earlier in this chapter, school connectedness is a key element of a safe and supportive school environment, which can help foster positive mental, emotional, and behavioral health outcomes. A few studies have examined student outcomes related to school connectedness, such as relationships between students and teachers (e.g., Cobbina et al., 2019; Fisher et al., 2019), relationships between students and other school adults (e.g., Cuellar et al., 2017), students’ perceptions as to whether school rules are fair or consistent (e.g., Booren et al., 2011; Fisher et al., 2019), and students’ perceptions of the school climate (e.g., Addington, 2018). However, the majority of these studies do not focus exclusively on metal detectors but rather on metal detectors used in conjunction with other school security measures.

Using data from the 2011 School Crime Supplement to the National Crime Victimization Survey, Fisher et al. (2019) studied 6,547 students aged 12–18; they found that the presence of metal detectors in schools was associated with weaker student–teacher relationships, but not with student perceptions of the overall fairness or consistency of school rules. Although metal detectors were relatively uncommon across schools, the authors note their disproportionate use in disadvantaged settings. After adjusting for student demographic characteristics, the study found that students in schools with metal detectors were more likely to perceive school rules as fair and consistently enforced. However, the authors cautioned that this finding is likely influenced by confounding between the presence of metal detectors and other student characteristics included in their adjusted model (Fisher et al., 2019).

On the other hand, broader research on school security suggests that school environments with higher security—including, but not limited to, metal detectors—may contribute to or reinforce such factors as lower student trust or perceptions of a punitive school climate, which have the potential to undermine students’ sense of connectedness (Gerlinger & Wo, 2016). However, because much of the existing literature examines multiple security measures

simultaneously, it remains challenging to isolate the specific impact of metal detectors on school connectedness. Thus, the committee did not identify definitive evidence linking metal detectors to adverse effects across dimensions of school connectedness.

Student Behavior

Research on the impacts of metal detectors on other student behaviors has yielded mixed findings. Some studies explored how the presence of metal detectors (as part of broader security measures) might influence student behaviors such as school avoidance (e.g., Bhatt & Davis, 2018; Tanner-Smith & Fisher, 2016), bullying and victimization (e.g., Schreck & Miller, 2003), or drug or weapon possession (Bhatt & Davis, 2018). However, these studies have not been able to isolate how metal detectors might affect specific behaviors.

A number of studies have explored the relationship between different forms of problematic behavior and the use of visible security measures. However, research on the specific impact of metal detectors on these behaviors is both limited and mixed. For example, Bhatt & Davis’s (2018) study on the effectiveness of weapons searches in Broward and Miami-Dade counties, Florida, found that metal detectors may deter students from bringing weapons to school, with findings showing a reduction in reported weapon possession and drug-related incidents in schools that conducted random searches, including those involving metal detectors (Bhatt & Davis, 2018). In their evaluation of School Crime Supplement data, Tanner-Smith & Fisher (2016) found that adolescents in schools that used metal detectors with security personnel reported higher rates of truancy than schools with no security measures; while utilization of security measures are intended to reduce problem behaviors, there may be unintended negative effects. By contrast, a review of literature on the impact of metal detectors was inconclusive about potential benefits of, or correlations between, metal detectors on student and staff behaviors (Hankin et al., 2011).

In summary, the studies reviewed by the committee that examined the relationship between use of metal detectors and effects on student behaviors relied primarily on cross-sectional and self-reported data, making it difficult to determine whether metal detectors are the cause of student behaviors or whether they are used in schools in response to existing student behavior and safety concerns. Overall, the committee found no strong evidence linking the use of metal detectors to changes in student behavior.

EVIDENCE ON THE PRESENCE OF SCHOOL SECURITY PERSONNEL

As noted previously, the committee includes a range of school personnel in the category of “school security personnel,” including school resource officers, other sworn law enforcement officers assigned to schools, and non–law enforcement security staff. Depending on the school context, this broad category may also extend to other school staff members with safety-related responsibilities. This section reviews evidence on how the presence of school security personnel may affect the mental, emotional, and behavioral health of students and staff. An aim of this review is to describe the complex interactions between security personnel and the school community, acknowledging both the potential protections and restraints associated with their presence.

Perceived Emergency Preparedness of Knowledge

The duties of school security personnel are generally framed around ensuring protection of students and staff in the event of an emergency and enhancing safety overall. However, the committee did not identify research that correlated the presence of school security personnel with perceptions of emergency preparedness among students and staff.

Perceptions of Safety or Fear

Most research on school security personnel has focused on students’ perceptions of fear and safety. As noted earlier, studies have examined multiple aspects of student fear, including fear of being a victim of crime (e.g., Fisher et al., 2018; Schreck & Miller, 2003), fear of going to and from school (e.g., Bachman et al., 2011b), and sense of safety at school (e.g., McDevitt & Panniello, 2005; Perumean-Chaney & Sutton, 2013; Theriot & Orme, 2014). Furthermore, studies have explored both the relationship between students’ perceptions of safety and the actual presence of school security personnel (e.g., Bachman et al., 2011a; Fisher et al., 2018; Perumean-Chaney & Sutton, 2013; Schreck & Miller, 2003; Tillyer et al., 2011), as well as the relationship between perceptions of safety and students’ attitudes toward these personnel (e.g., Brown, 2005; McDevitt & Panniello, 2005; Theriot, 2016). However, although several studies examine the presence of school security personnel in relation to students’ perceptions of safety or fear, these studies generally do not isolate security personnel as the primary factor influencing those perceptions or establish a causal relationship.

Studies have yielded mixed findings regarding the effects of security personnel on perceived safety. Some students and staff report feeling safer with a security presence, especially in schools with high crime rates; however, the school and community contexts limit the extent to which findings are broadly generalizable (Cobbina et al., 2019; Theriot & Orme, 2014). Students in other studies have reported that security guards had little to no influence on their perception of school safety (e.g., Bachman et al., 2011; Booren & Handy, 2009).

Theriot & Orme (2014) analyzed data from 1,956 middle and high school students from a school district in the southeastern United States, examining how school resource officers affected students’ feelings of safety. They used latent class analysis to categorize students into two groups: those who felt safe and those who did not. They found mixed outcomes: while interactions with these officers were not associated with increased feelings of safety overall,

male students who had reported feelings of school connectedness and had positive attitudes about school resource officers reported feeling safer in their school environment (Theriot & Orme, 2014). While there was no significant relationship between students’ number of school resource officer interactions and feelings of safety, having positive attitudes toward these personnel was associated with students being categorized in the group with higher feelings of safety (Theriot & Orme, 2014).

Similarly, in a national evaluation of the school resource officer program in three states, McDevitt & Panniello (2005) found that middle and high school students who had a positive opinion of their school resource officer and felt comfortable reporting crime to them reported more positive perceptions of school safety. And Brown (2005) found that high school students in a majority Hispanic school district in Texas agreed that police officers and security guards did a good job keeping their schools safe.

By contrast, an analysis of National Crime Victimization Survey data by Bachman et al. (2011b) found that White students reported heightened fear of victimization when security guards were present in a school, a pattern not observed among African American students. In a separate study, Brown & Benedict (2005) reported that male students and students with prior victimization experiences were less likely than their peers to view school resource officers as contributing to school safety.

Across studies, the need for additional research—and replication of existing research— using longitudinal data is highlighted as a need to further clarify the real and perceived effects of school security personnel on safety and to identify differences in findings based on the type of personnel that is present in a school. As noted previously, existing research does not always link these feelings of safety or fear to the presence of security personnel directly, which may indicate that there are other elements of the school or community environment that increase the likelihood of security personnel being present and that may be contributing to perceptions of fear.

Student Trauma or Mental Health Concerns

The committee did not identify studies that directly assessed the effects of school security personnel on student trauma or mental health challenges. Although existing studies primarily focused on related but distinct topics, such as students’ perceptions of safety or fear, the committee did not find evidence that school resource officers or other law enforcement or security staff contribute to trauma or mental health challenges among students or staff.

Student Perceptions of School Connectedness

The presence of security personnel in schools has been associated with mixed effects on school connectedness. Two studies examined the relationship between the presence of school security personnel and students’ perception of school connectedness. Fisher et al. (2019) used survey data from 6,547 students to model associations between school security measures, including security personnel, and student perceptions of social control. They found that the presence of security personnel was associated with students’ poorer relationships with teachers—a measure of school connectedness. Presence of school security personnel was not found to affect the relationships between students and other adults in the school. The authors note that future research is needed to replicate their findings with longitudinal data and that the survey data used in their analysis did not allow them to examine intraschool variability at the individual or group level (Fisher et al., 2019).

In an analysis of survey data from 1,956 middle and high school students, Theriot (2016) found differences in feelings of school connectedness related to interactions with school resource officers. The surveyed students were from 12 schools within a single school district and each school had a full-time school resource officer. School resource officers were expected to provide law enforcement, education, and mentoring to students, educators, and other school staff. Analyses showed that while more interactions with school resource officers increased students’ positive attitudes about them, those

interactions decreased perceptions of school connectedness (Theriot, 2016). The findings suggest that the surveyed students did not generally view the presence of school resource officers negatively. A possible explanation for lower reported school connectedness is that the presence of the school resource officers in these schools may have increased students’ perception that their school was less safe, perhaps leading to feelings of discomfort or disconnection at school.

Further research is needed to understand how all types of school security personnel may affect students’ feelings of school connectedness and whether those perceptions vary across a wider variety of school contexts and student populations.

Student Behavior

Research on the relationship between school security personnel and student behavior has focused primarily on school discipline as an outcome. However, the use of disciplinary practices as an outcome measure suggests that student behavior has not typically been used as an indicator of students’ overall well-being. For this reason, the committee’s review of literature also includes findings on specific student behavioral outcomes that may more clearly reflect student experience, such as school avoidance, truancy, and absenteeism. However, findings are mixed and do not establish a strong causal link between the presence of school security personnel and student behaviors.

Tanner-Smith & Fisher (2016) used both the SCS and SSOCS to examine the relationship between visible school security measures, such as school security personnel, and attendance from the perspectives of students and school administrators. Based on student-reported data, adolescents in schools using only security personnel reported significantly higher truancy than those attending schools with no security measures or only cameras. Additionally, administrator-reported data showed lower attendance rates in schools that used security personnel, metal detectors, and cameras compared with those that used no security measures or only security personnel. The authors note that differences in responses between

students and administrators may be related to differences in awareness of security measures being utilized in schools (i.e., students may not recognize the presence of all security measures). Tanner-Smith & Fisher (2016) also caution that they were unable to examine the effects of school-level contextual factors.

Other studies have yielded similar findings. Randa & Wilcox (2010) used a national sample of 3,776 students to examine school avoidance behaviors, including avoidance of specific school locations (e.g., hallways, restrooms, parking lots), school extracurricular activities, specific classes, and avoidance of school altogether. While the presence of school security personnel was not the only focus of this study, presence of security guards was included as a security measure in respondents’ schools that was potentially related to the reporting of general avoidance behaviors (i.e., avoidance not tied to a specific location within the school). The presence of security personnel was significantly associated with students’ reporting of general avoidance (Randa & Wilcox, 2010).

Additionally, Gardella et al. (2016) analyzed survey data from 5,930 adolescents aged 12–18, examining the relationship between school security measures, including security guards, and effects of victimization at school. They found that the presence of school security personnel moderated the relationship between victimization at school and absenteeism, such that their presence was associated with increased student absenteeism. Adolescents who experienced victimizations in schools with security guards were absent nearly twice as often (2.01 days absent per month) compared with students experiencing victimization in schools without a security guard (1.28 absences per month). Gardella et al. (2016) noted that more research is needed to understand how within-school differences affect experiences and how school environments where security measures are used may have a confluence of variables that influence student perceptions and behaviors.

CONCLUSION

Existing research on school security measures, while providing some insight into their effects on mental, emotional, and behavioral health outcomes, remains methodologically thin, particularly in terms of causal inference, long-term impact assessment, and population-level differences in outcomes. While the literature reviewed in this chapter addresses a range of security measures, the committee found that the evidence base is too limited to draw definitive conclusions about variations in outcomes. In particular, the current research does not adequately capture whether positive effects or adverse impacts differ by characteristics such as student age, race, or ethnicity; school urbanicity; or school infrastructure.

The predominance of cross-sectional studies highlights the absence of rigorous empirical evaluations, underscoring the urgent need for more quasi-experimental and experimental designs to establish causal relationships. Additionally, longitudinal studies are essential for understanding the sustained effects of security policies on the well-being of students and staff. Future research that adopts rigorous approaches to examine how security measures differentially affect student populations will be of particular importance, given the wide variation in school contexts and the varying needs of students at different developmental stages and at different levels of vulnerability to adverse outcomes.

Comparative studies evaluating the relative effectiveness of alternative strategies—such as mental health interventions and traditional security measures—are needed to identify more holistic approaches to fostering safe and supportive school environments that can help mitigate potential negative impacts on students and staff.

Strengthening research methodologies across these dimensions will be critical for informing policies that not only enhance security but also promote the well-being of all students and staff. Further research, particularly experimental and longitudinal studies, is needed to provide definitive conclusions on best practices for school safety and the implementation of school security measures.

A positive school environment that fosters positive mental, emotional, and behavioral health, characterized by trust, strong student–teacher relationships, and proactive mental health support, can shape how students and staff experience and respond to school safety and security practices. Schools that focus primarily on security measures without fostering a supportive climate may inadvertently contribute to student distress, making school safety and security practices feel punitive or fear inducing rather than educational and supportive.

The effects of school security measures appear to be influenced by the context in which they are implemented. While measures such as locked doors tend to be perceived as protective, use of metal detectors and routine presence of security personnel may exacerbate feelings of surveillance and criminalization for some students, particularly in marginalized communities. These findings suggest that a one-size-fits-all approach to school security is insufficient and that policymakers need to consider the unique social and environmental contexts of each school.

Overall, schools that balance physical security with a positive school climate may be better positioned to implement other school safety and security practices, including school active shooter drills, in a way that enhances preparedness while minimizing adverse effects on students and staff.

REFERENCES