32.3 Mass Violence

Mass Shootings in the United States

Statistically, mass violence is uncommon, with mass shootings comprising most incidents. There is no standard definition of mass shooting, but there is a common definition for active shooter. An active shooter is an individual who is killing or attempting to kill people with a firearm within an area (USA Facts, 2023). Criteria to report mass shootings differ by the number of victims, whether injuries are included, the location of the shooting, whether it occurred with another crime, and the relationship between the shooter and the victims (Smart & Shell, 2021). More common definitions include an incident where four or more people have been murdered by a firearm or an event where at least four victims were injured or killed by a firearm. Although less than one percent of all firearm deaths annually in the United States are attributed to mass shootings, they have incited fear and panic beyond the direct victims and their families (Soni & Tekin, 2022). In the United States, the rate of mass shootings and the number of people killed over the last four decades has increased, resulting in over 1,000 deaths and 1,500 injuries (NCMDI, 2019; Soni & Tekin, 2022). Federal funds to study gun violence were largely unavailable for about 20 years, but in 2019 the U.S. Congress approved funding for the CDC and National Institutes of Health to conduct gun violence research. This opened the door to new research on gun violence, suicide, and injury prevention (Weir, 2021). Table 32.6 provides 2016–2022 statistics, highlighting the recent increase in mass shootings. Table 32.7 compares the outcomes of the deadliest mass shooting incidents in the United States.

The Impact of Mass Violence

Mass violence and shootings have significant mental health effects on population health. These terrifying and traumatic incidents are often directed at strangers in public places. The community’s response is defensive and urgent, demanding an explanation to try to make sense of the nonsensical. In the aftermath of mass violence, political leaders often blame mental illness, a narrative that echoes the public’s common belief that individuals with mental illness generally pose a danger to others. It is difficult to comprehend the logic of mass violence or to imagine that a mentally stable person would intentionally kill multiple strangers; therefore, one might conclude that all perpetrators of mass violence must be mentally ill (NCMDI, 2019). However, according to a report from the U.S. Department of Homeland Security, the motives for mass violence are complex. The most common reasons relate to grievances, ideology, bias, political beliefs, and psychotic behavior (Alathari et al., 2023). Some offenders give multiple reasons for committing acts of mass violence, and others, killed during the event, never provide a reason. Table 32.8 outlines cited motivations for mass violence events. Over half are attributed to personal, domestic, or workplace grievances, while only 14 percent are related to psychotic symptoms (Alathari et al., 2023).

Mental health issues related to mass violence events are correlated to direct victims, their families, and the general population. Research has shown that 48 percent of Americans live with the fear of becoming a victim of a mass shooting, and more than 10 percent have avoided large crowds or bought a weapon because they are worried about the threat of mass shootings (Brenan, 2019). Individuals living in the community or attending the school where a shooting has occurred have increased emotional distress, with a higher likelihood of taking antidepressants, engaging in risky behaviors, or considering suicide (Brodeur & Yousaf, 2022; Deb & Gangaram, 2023).

Public health and community health nurses and other health providers must be aware of the role of mental illness in mass violence for both victims and offenders to provide support and lead efforts to prevent mass violence (Alathari et al., 2023). Like many other community health concerns, preparation and prevention are key strategies for combating mass violence. Planning and participation in regular preparation activities like active-shooter drills supports proactivity and preparation for the worst-case scenario (Peterson & Densley, 2021).

A part of preparation, albeit not coordinated, is attention to warning signs. Warning signs include having behavioral problems or difficulty connecting with others, being noncommunicative, having aggressive or violent verbalizations, being withdrawn, harming self or others, and being emotionally unstable (Peterson & Densley, 2021). Education and advocacy programs for teachers, caregivers, and the public can go a long way in promoting awareness of behaviors that might be precursors to violence in individuals. Seemingly innocuous comments or interactions may be warning signs or cries for help (Peterson & Densley, 2021).

Mass Casualty Management

Mass casualty incidents (MCIs) are human-made or natural disasters that overwhelm the resources of local management agencies and the health care system. Emergency medical services (EMS) are often the first responders on the scene of a mass casualty event, but the principles of response apply to any health care responder. First responders are critical in triaging, stabilizing, and preparing to transport victims to health care facilities after MCIs. As the name implies, MCIs involve large numbers of victims who will need varying levels of care. Effective management, communication, and collaboration are essential during an MCI. Local community agencies, such as the fire department or police department, may respond, and state or national agencies may also become involved, depending on the type and severity of an MCI (Alpert & Kohn, 2023). 

Response to a mass casualty event is complex, involving many people from different disciplines. Planning is a critical step to response, as a methodical approach to a crisis engages community responders in thinking through the lifecycle of a potential crisis, determining required capabilities, and establishing a framework for roles and responsibilities (FEMA, 2021). Since mass casualty disasters can happen without warning, a constant state of readiness requires training and regular drills. Simulations are frequently used to prepare health care workers and first responders for mass casualty management, as individuals must understand the roles that each one has in mass casualty response (Figure 32.3).

Figure 32.3 EMS staff participate in a training exercise to prepare for a mass casualty incident. (credit: “Mass Casualty Incident Training, Mammoth Hot Springs” by Neal Herbert/NPS/Flickr, Public Domain)

Multiagency, Interprofessional Team Coordination

The National Incident Management System (NIMS) provides a framework for the management of disasters and MCIs. NIMS guides the multiagency, interprofessional structure and organization for communication and incident command, allowing for efficient communication using common terminology, clarification of leadership and roles, and effective management and distribution of resources. Figure 32.4 illustrates the organization of Incident Command System (ICS) used in NIMS. Table 32.9 provides further description of the roles of command staff in the ICS.

Figure 32.4 The ICS provides responders with a framework for organization, decision-making, and communication during a disaster or mass casualty event. (credit: modification of work “ICS Command Function Organization Chart” by FEMA, Public Domain; attribution: Copyright Rice University, OpenStax, under CC BY 4.0 license)

Role	Function
Incident Command	Has overall responsibility for the incident Sets objectives for the incident and approves the incident action plan Manages the incident and approves requests
Public Information Officer	Develops and coordinates press releases Monitors and maintains information related to the incident
Safety Officer	Identifies and mitigates hazards Approves the Medical Plan Ensures safety messages and briefings are made throughout the incident
Liaison Officer	Communicates with cooperating agencies Maintains list of responders and responding agencies Monitors resources, providing current resource status, including limitations and capabilities of agency resources
Operations Section Chief	Organizes services and resources to carry out the plan Supervises operations Requests additional resources if needed
Planning Section Chief	Develops incident action plan to accomplish incident objectives Collects data related to the plan Facilitates meetings Assembles task forces if needed
Logistics Section Chief	Provides facilities, transportation, communications, supplies, fuel, food, and medical services for incident personnel Manages incident logistics Identifies anticipated services and support Oversees communications, medical, and traffic plans Oversees demobilization of logistics section and resources
Finance/Administration Section Chief	Monitors incident costs Provides financial guidance
Intelligence/Investigations Section Chief	Scope and function determined by the Incident Commander May be incorporated as a part of the planning section, operations section, or general staff section Prevents unlawful activity during incident Collects, processes, and analyzes information, evidence, and intelligence Investigates the cause of the incident and identifies suspects Conducts missing persons investigations

Table 32.9 ICS Command Roles and Functions (See FEMA, 2018.)

The Medical Branch (nurses and other health care staff) reports to the Operations Section Chief. This includes the medical director, who supervises triage, treatment, and transport of clients; the triage officer, who oversees triage of clients; the treatment officer, who manages the treatment area; and the transport officer, who arranges and documents transport of clients from the scene (Lincoln et al., 2023). Additional roles may be added depending upon the number of clients and the time needed to manage medical needs.

Zoning of Care Areas

In an MCI, the area of care is divided into zones if there is a risk of chemical, biological, radiological, or nuclear contamination (Figure 32.5) (Alpert & Kohn, 2023).

• The hot zone is the immediate location of the incident, where victims and responders have direct contamination. 
• The warm zone is the area surrounding the hot zone where contamination is present from victims or responders leaving the hot zone. Triage and decontamination can occur in the warm zone to neutralize the risk to victims.
• The cold zone is where care for victims occurs and may serve as the location for minor casualty holding or release.

Figure 32.5 During an MCI, responders divide care into hot, warm, and cold zones if there is a chemical, biological, radiological, or nuclear contamination risk. (attribution: Copyright Rice University, OpenStax, under CC BY 4.0 license)