School shootings in Boston, Baltimore, NYC: skills for prevention
Research by Hugi Hernandez, Founder of Egreenews
Mass shootings at K-12 schools remain among the most distressing public safety challenges in the United States. Although statistically rare, their psychological and social impact is profound. Between 2019 and 2020, the growing number of mass shootings was associated with an average distance of less than 0.60 miles from the shooting location to a public or private school, highlighting the danger posed to children living and learning in these areas [1†L9-L14].
This report examines the academic evidence on school shooting prevention, with a focus on the specific skills school administrators in public and private schools in Boston, Baltimore, and New York City can employ. It synthesizes peer-reviewed research published between 2021 and 2026 from more than a dozen universities, including Boston University, Johns Hopkins University, Columbia University, and the University of Virginia.
Three key findings emerge from this evidence review:
- Behavioral threat assessment teams are the single most widely adopted and effective prevention strategy, with adoption increasing from 65% to 85% of U.S. schools between 2021 and 2024. However, effectiveness depends on proper implementation and a focus on student support rather than punitive responses.
- Active shooter drills are associated with significant psychological harm, including a 39–42% increase in anxiety and depression following drills, while evidence of their life-saving efficacy remains limited.
- The public health approach—emphasizing school climate, mental health support, and community partnerships—outperforms purely physical security measures in preventing violence, though the two approaches are not mutually exclusive.
1. The scope of the challenge: Mass shootings at schools
School shootings in the United States have increased precipitously since 2017, with approximately 100,000 K-12 public schools serving 51 million children nationally [7†L23-L27]. While mass shootings account for a small fraction of overall homicide, they produce an outsized psychological and social impact, reshaping how people experience public space and safety [10†L32-L37].
A descriptive analysis of school shootings across five decades found that mass shootings remain rare relative to non-mass school firearms incidents. Only 10% of school shooting incidents caused four or more total bullet wound injuries, while 16% displayed indicators of mass-violence intent. Behavioral health issues were commonly identified among perpetrators [1†L16-L21].
Research from Columbia University’s Mass Murder Database, examining 82 incidents of mass murder in academic settings, found that severe mental illness was absent in the majority of attackers. When present, it was more associated with mass murders where weapons other than firearms were involved. The study concluded that focusing on mental illness as the primary cause risks missing other contributing factors and exacerbates stigma [34†L4-L48].
Understanding the distinction between mass and non-mass school shootings is critical for prevention. While mass events capture public attention, the majority of school firearm incidents do not meet the criteria for mass shootings, suggesting different prevention strategies may be needed for different types of incidents [1†L16-L21].
2. Core prevention skills for school administrators
2.1 Behavioral threat assessment and management
Behavioral threat assessment is a violence prevention strategy adapted for use in schools. The Comprehensive School Threat Assessment Guidelines (CSTAG), developed at the University of Virginia, is designed to recognize the developmental needs of youth and the mission of schools to help all students be successful [27†L10-L15].
A multidisciplinary CSTAG team employs a five-step decision tree to consider a student’s intentions and behavior context, distinguishing transient threats that are not serious from the small proportion of substantive threats requiring protective action. Crucially, CSTAG teams are oriented to helping students resolve conflicts underlying threatening behavior, rather than responding with punitive, zero-tolerance approaches. Six controlled studies have supported the safety and effectiveness of the CSTAG model [27†L16-L25].
Adoption of threat assessment teams has grown rapidly. During the 2021-22 school year, 65% of schools across the United States reported having a threat assessment team. By April 2024, this number had jumped to 85% [2†L28-L31]. A 2026 study found that school threat assessment teams can manage student threats of violence with few subsequent attacks but should anticipate that threat classification is strongly associated with the likelihood of an attack [2†L33-L39].
“Schools are not as dangerous as the public perceives, but less obvious problems in the school climate such as bullying and harassment require attention.”
— Dewey Cornell, University of Virginia, 2021 [27†L19-L22]
2.2 School climate as a prevention foundation
School climate has received considerable attention in the literature and educational policy as a potential target for school improvement and school safety efforts. A comprehensive review published in 2021 concluded that while additional research is needed to determine the most effective approaches for optimizing school climate, there is compelling correlational and experimental evidence that it is an important factor in a comprehensive approach to school safety [28†L27-L49].
A systematic review and meta-analysis published in 2021 estimated a significant positive relationship between attitudes toward violence and school violence in children and adolescents, underscoring the importance of shaping student attitudes through positive school environments [16†L52-L56].
For administrators, this means developing skills in measuring school climate, using data-based decision making, implementing school-wide programming, and building a culture where students feel connected, respected, and supported [28†L27-L49].
2.3 Active shooter drills: Benefits and trade-offs
Approximately 95% of U.S. public schools conduct active shooter drills annually. However, the lack of consistent standards has led to significant variations in implementation, raising questions about both efficacy and possible negative impact on students and staff [4†L27-L34].
A landmark 2021 study published in Humanities and Social Sciences Communications applied machine learning and interrupted time series analysis to 54 million social media posts from 114 schools spanning 33 states. The results indicated that anxiety, stress, and depression increased by 39–42% following drills. Importantly, the research noted that this increase in psychological distress was accompanied by increases in civic engagement (10–106%). However, the study concluded that this research, paired with the lack of strong evidence that drills save lives, suggests proactive school safety strategies may be both more effective and less detrimental to mental health than drills [29†L8-L23].
School administrators face a difficult balancing act: responding to legitimate safety concerns while avoiding unnecessary psychological harm. Best practices emerging from the research include age-appropriate drill design, advance notification to parents and students, avoiding trauma-simulation techniques (such as masked “shooters” or simulated gunfire), and providing mental health support following drills [29†L8-L23].
2.4 School resource officers: Mixed evidence
The role of armed law enforcement in schools remains contested. A 2021 study using linked disciplinary, academic, juvenile justice, and adult conviction data from North Carolina found that School Resource Officers (SROs) not only decrease the incidence of serious violence but also increase the use of out-of-school suspensions, transfers, expulsions, and police referrals [30†L6-L17].
About 45 percent of public schools reported having sworn law enforcement officers who routinely carried a firearm in 2021-22, down from 51 percent in 2019-20 [18†L47-L51]. Research from the University at Albany and RAND concluded that school resource officers do not prevent school shootings or gun-related incidents, though they may be effective in addressing other forms of school violence [3†L36-L39].
For administrators, the implication is that SROs should not be relied upon as a primary prevention strategy for mass shootings. If deployed, their role should be clearly defined, with emphasis on relationship-building, de-escalation, and appropriate training for working with youth, rather than purely law enforcement functions [30†L6-L17].
3. Location-specific insights: Boston, Baltimore, and New York City
3.1 Boston
Research led by Boston University School of Public Health has provided critical insights into the timing of child firearm injury risk. A 2025 study focused on public school students in New York City—but with implications for Boston and other urban districts—found that the risk of child firearm injuries was 45% higher during the 2-6 pm afterschool period on school days compared to non-school days [7†L6-L9]. This finding suggests that prevention efforts must extend beyond school buildings and hours.
Boston University researchers have also emphasized the importance of early warning systems for targeted violence. Most perpetrators of mass shootings exhibit pre-incident indicators, providing a window for intervention—a finding that supports the threat assessment approach discussed above [10†L5-L10].
A study examining peer death exposure among Massachusetts public school students found that in any given year, 5 percent of high school students have a grademate die. Experiencing a grademate’s death lowers test scores, attendance, GPA, and high school graduation rates, with stronger effects for low-income, Black, and Hispanic students [33†L5-L18].
3.2 Baltimore
Johns Hopkins University researchers have been at the forefront of school violence research. A 2021 study examining the association between adolescents’ concerns about school violence or shootings and mental health outcomes found that concern, worry, and stress related to school violence may be risk factors for internalizing problems, with variation in the strength of association by race/ethnicity [31†L11-L18].
Research on student mobility and violent crime exposure at Baltimore City public elementary schools examined whether changes in violent crime at schools are associated with the likelihood of school exit, highlighting the interconnectedness of school and neighborhood violence [6†L26-L31].
Baltimore’s Safe Streets program, a community violence intervention, has been evaluated for its effectiveness in reducing homicides and non-fatal shootings among youth ages 15-24, demonstrating the potential of community-based approaches that complement school-based prevention [6†L6-L10]. A Johns Hopkins study found that attending a high-surveillance school significantly decreases 12th grade math test scores and decreases college attendance, with higher rates of suspensions for minor offenses [20†L34-L39].
3.3 New York City
Columbia University’s Teachers College and Mailman School of Public Health host significant gun violence prevention research capacity. The Columbia Scientific Union for the Reduction of Gun Violence (SURGE) brings together interdisciplinary approaches to combating gun violence, including school violence prevention research led by Professor Sonali Rajan [13†L4-L11].
Research from Columbia has emphasized that current safety efforts—which include active shooter drills, arming teachers, and providing students with bulletproof backpacks—focus almost entirely on how to respond in the aftermath of an attack rather than on primary prevention [13†L49-L54]. This aligns with the broader public health approach to school safety.
A study published in Preventive Medicine in 2022 called for a more expansive school gun violence prevention framework that broadens the spectrum of what constitutes “school gun violence prevention,” moving beyond reactive measures to comprehensive, multi-layered strategies [7†L28-L35].
4. Public versus private schools: Different contexts, common principles
Research specifically comparing public and private school safety remains limited. However, the proximity of mass shootings to both public and private schools has been documented. A 2021 study analyzing mass shootings and their proximity to a public or private school highlighted the danger posed to children in both settings [1†L9-L14].
A National Threat Assessment Center study found that out of 67 prevented attacks on schools, only one case was at a private school. Private schools may be less susceptible to violent attacks because they are typically comprised of smaller, more involved communities [9†L49-L52]. However, private schools generally do not face as many requirements as public schools for developing security plans, creating potential gaps in prevention capacity [19†L37-L43].
For private school administrators, the core skills remain similar: developing threat assessment capacity, improving school climate, implementing evidence-based drills, and building community partnerships. The key difference is that private schools often have smaller scale, potentially enabling more personalized prevention approaches but may lack the formal support structures available to public school districts.
5. Synthesis and implications for administrator training
The evidence reviewed points to a coherent set of skills that school administrators—in both public and private schools across Boston, Baltimore, NYC, and beyond—should develop:
- Threat assessment implementation: Administrators must learn to establish multidisciplinary teams, use standardized assessment protocols (such as CSTAG), distinguish transient from substantive threats, and focus on student support rather than punishment.
- School climate improvement: Skills in measuring climate, interpreting data, implementing evidence-based programs, and fostering positive relationships between students and staff are essential.
- Evidence-based drill design: Administrators need training to design drills that minimize psychological harm—avoiding trauma simulation, providing advance notice, ensuring age-appropriate content, and offering mental health follow-up.
- Resource deployment evaluation: Where SROs are used, administrators need skills to define clear roles, ensure appropriate training, and monitor both safety outcomes and potential negative consequences such as disproportionate discipline.
- Community and family engagement: Building trust and communication channels with families, mental health providers, and community organizations strengthens the protective network around students.
“A public health approach to addressing firearm violence in schools is the most effective way to prevent school shootings, even if these effects are indirect through improvements in student social competence and positive school climate.”
— Reeping et al., 2022 [1†L33-L38]
Data on implementation fidelity remains incomplete. A 2026 study examining school team fidelity in behavioral threat assessment noted that the widespread adoption of behavioral threat assessment has generated a need to measure its fidelity of implementation, opening avenues for future research [2†L20-L26].
6. Conclusion
The evidence base for school shooting prevention has matured considerably over the past decade. School administrators have access to validated tools and strategies, particularly behavioral threat assessment and school climate improvement. However, significant challenges remain. The rapid expansion of active shooter drills has outpaced evidence of their effectiveness, and their associated psychological harms are now well-documented. The role of school resource officers remains contested, with evidence suggesting trade-offs between violence reduction and increased disciplinary action.
For administrators in Boston, Baltimore, and New York City, the core challenge is implementation fidelity—ensuring that prevention strategies are executed as designed, with appropriate training, resources, and attention to potential unintended consequences. A public health approach, emphasizing student well-being, positive school climate, and early intervention, appears to offer the most promising path forward. Physical security measures are not mutually exclusive with this approach, but they should be implemented in a way that does not undermine the trusting relationships that form the foundation of school safety.
The research community continues to refine understanding of what works. Future studies should focus on implementation fidelity, long-term outcomes of different prevention strategies, and comparative effectiveness across different school contexts, including the differences between public and private schools and across different geographic regions.
Discussion questions, key takeaways & call to action
Reflective questions for school communities
Use these questions to guide staff meetings, professional development, or community conversations:
- Does your school currently have a behavioral threat assessment team? If yes, how is it trained to distinguish transient threats from substantive ones? If no, what steps would be needed to establish one?
- How does your school measure “school climate”? What data do you collect on student connectedness, bullying, and feelings of safety?
- Are your active shooter drills age‑appropriate and announced in advance? Have you surveyed students or staff about anxiety following drills?
- If your school uses School Resource Officers, what is their primary role: relationship‑building and de‑escalation, or law enforcement? How do you monitor disciplinary outcomes?
- How does your school extend prevention beyond school hours, given the 45% higher risk of firearm injury from 2–6 pm on school days?
- What is one change you could make this semester to shift from reactive security to proactive, public‑health‑informed prevention?
Key takeaways from the evidence
- Threat assessment works when implemented with fidelity. Adoption has grown to 85% of U.S. schools, but quality varies.
- Active shooter drills cause measurable psychological harm (39–42% increase in anxiety/depression) with no proven life‑saving benefit.
- School climate is a prevention asset. Positive relationships and connectedness reduce violence risk.
- SROs have trade‑offs. They may lower serious violence but increase suspensions and police referrals, and they do not prevent mass shootings.
- Prevention must be multi‑layered – threat assessment + climate + community partnerships + evidence‑based drills.
- Private schools are not immune but face fewer mandates; voluntary adoption of best practices is critical.
- Research gaps remain – especially on implementation fidelity, private school data, and long‑term outcomes.
Call to action: Share this report
Use the following hashtags when sharing this research on social media to reach educators, policymakers, and parents:
Copy and paste these hashtags into your posts. Better yet, link to this report and tag your local school board or state education department.
References
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