Mass shootings are a type of terrorism. Unlike natural disasters that require crisis intervention, mass shootings are caused by human beings. The evil, cruelty, un-necessity, and un-answered questions are far more disturbing than by a random hurricane or powerful natural event and leave far deeper trauma for people after the crisis has dissolved.
Please also review AIHCP’s Crisis Intervention Certification and also its Trauma Informed Care Certification
Definitions of Mass Violence and Trauma
While mass shootings themselves are a rare event, over the last ten years, they have become far more lethal with higher fatalities (O’Connor, et al., 2025). While gun violence and shooting is part of many crimes, not all gun violence is considered mass shooting. A mass shooting requires 3 or more fatalities, not including the shooter (O’Connor, et al., 2025). In addition, a mass casualty incident represents a single incident that also strains and overwhelms the resources of local emergency medical services (Webber & Mascari, 2018). While the term mass shooting can be applied, mass bombings, or any type of mass casualty event shares the common horrific psychological and communal reactions. The incident effects the present moment that must be dealt with in the heat of crisis but also later healed through enormous amounts of time due to the trauma instilled upon victims, survivors, spectators, first responders and counselors.
Acts of terrorism and mass shootings are the most common types of mass casualty events. Terrorism according to Webber is the intentional act of malevolence and murder to instill societal dread and fear which erodes society’s sense of safety and security (2018). Mass Shootings are events including the death of 3 or more victims not including the shooter, but these events are more than merely gang violence but also deeper seeded issues of mental instability and hatred with no true logical reasoning. Webber states that these events are intentional and violent, and also sudden and unexpected. The connection between the victims and the shooter is sometimes distant and unrelated but universal instead of deeply personal. Many family members and victims in turn face deeper grieving issues due to the intimately tied trauma tied to it (2018). Following all of these incidents is also an overwhelming presence of media attention that lead to many additional issues in facing the trauma and the grief.
Historical Events
According to the FBI, there has been 141 mass shootings in the last 23 years. Of these shootings, 137 of the 141 involved a single shooter. Among the victims during that span, 2249 victims have either been murdered or injured, with countless others traumatized. Of the victims, 1308 (58%) were murdered and 935 (42%) were injured (O’Conner, et al., 2025).
Among some oft the most notorious and lethal shootings include the Las Vegas shooting which killed 58 people, injured another 546 on October 1st, 2017, the Pulse Night Club shooting in Orlando which killed 49 individuals and injured another 53 on June 12th, 2016, the VA Tech shooting which killed 32 people and injured another 17 on April 16th, 2007, the Boston Bombing which killed 3, injured 264 and maimed 16, Sandy Hook Elementary in Newtown CT which killed 26 and injured 2 on December 14th, 2012 and Columbine in Colorado where 13 were killed with an additional 21 injured on April 20th, 1999 (Webber & Mascari, 2018).
Profile of the Offender
The FBI has extensive research on the profile of the a shooter. From terrorist to lone wolf domestic and mentally unstable individuals, shooters share many common features. O’Connor lists that from 145 shooters identified in the last 20 years, the average age is 34, 139 of them were males (95 %), 80 were white (55%), 69 had psychiatric issues (48%) and 43 had a past violent history(30%) (2025).
Unfortunately, many shooters do not have a past criminal history and one needs to look for cues from family history, mental records (which are usually confidential), and from social media warnings. Many display anti-social tendencies, but also paranoia, psychosis, and feel victimized by society. Due to this, they feel less anxiety, remorse or empathy for what they do (Teddy, M., 2013). Many of the individuals are also marginalized from society of different faith or beliefs, as well as considered culturally or socially as outcasts due to bullying. These individuals suffer follow a pattern stemming from poor mental health that leads to eventual suicidal ideation. The may consider themselves seeking fame and glory and sending a message in various scripts found in journals or expressed on social media. These random messages later escalate to threats which later lead to more detailed planning of rampage (Webber & Mascari, 2018). Many shooters may not have a specific individual they seek to punish but society as a whole, a collective group, religion, sexual group, or past school administrations (Cimolai, et al., 2021). In their planning, the most utilized weapon is a hand gun (80%), followed by rifle (35%), multiple weapons (29%) or shotgun (19%).
Shooters for whatever mentally disturbed reasons target commercial (44%), workplaces (31%), open spaces (10%), places of worship (8%), schools (9%) and government facilities (7%) (O’Conner et al., 2025).
Crisis and Emergency Response
Emergency responses include a varied tier of coordination between local, state and federal authorities that involve a complicated chain of command with a diverse set of skills to handle a variety of issues. The initial response of law enforcement to an active shooting is key as well as the response of victims at a scene. In addition to the first response and neutralization of the shooter, include responses to the victims who are deceased, injured or traumatized. Beyond this basic on the scene response also includes a complicated chain of command which allocates roles and resources to the situation in the immediate moment, following days and overall recovery to the community. The U.S Department of Homeland Security can assist local and state authorities in mass casualty events whether via FEMA for natural disasters, or also in cases of extreme acts of terrorism and violence. This involves an Incident Command Center with staff that carries out various duties that include evacuation and treatment of victims, ER and medical preparation at hospitals dealing,, family and victim resources, victim assistance, shelters, psychological first aid, news and media updates, allocation of resources of volunteers, blood, food, clothing and shelter. Through detailed plans and leadership line of commands, the process can be streamlined to meet the immediate needs of individuals (Webber et al., 2018).
For those who suffered the death of loved ones, plans include responses to these dire needs. On site inspection and criminal investigation, morgue and body collection, as well as joint family assistance to help families find their loved ones, or if a member is deceased a professional and pastoral way to notify family, help them identify and collect family remains. Finally, coordination with the death care industry which prepares the body for funeral and memorial (U.S. Department of Homeland Security, National Response Plan, 2004).
Crisis Teams and counselors play a key role in helping individuals after the immediate event who are victims or spectators or members of the family find resources, emotional regulation, psycho-education and referrals to emotional needs. They primarily apply the standards of Psychological First Aid. Please refer to AIHCP’s blog on Psychological First Aid. Click here. In addition plans should be in motion to also help with counselors and mental health professionals who may experience vicarious trauma or secondary trauma (U.S. Department of Homeland Security, National Response Plan, (2004).
After the shooter is neutralized, the crisis teams under the command of authorities are able to help individuals find the emotional needs they require. Among those within the hot zone of the incident include a wide variety of different people affected at different levels by the tragedy. The Popular Exposure Model lists individuals within certain letter categories. Community victims murdered, injured or bereaved family members constitute group A. Community victims exposed directly to the event consist of group B. Bereaved extended family or residents near the event compose group C. First responders, clergy and mental health professionals consist of group D. Those who identify with the victims due to religious affiliation, sexual orientation, cultural ties, or shared professions consist of group E and finally the community at large create group F (Webber & Mascari, 2018).
After the immediate chaos is resolved, safety and order is restored and the community processes the horrible nature of the event, the community begins to heal through a series of emotional outcries and important grieving events. Outrage over the incident, political dissent over policies, analyzation of local response, and public discourse follow. Memorials, vigils and funerals proceed and individuals turn to later social action to find meaning in the meaningless (Webber & Mascari, 2018).
Short and Long Term Psychological Trauma
While not all traumatic events in life will result in long term issues, most suffer from Acute Stress Disorder in the aftermath of an experience (DSM-V-TR, 2018). Ironically, human resiliency is stronger than many think and how individuals recover vary on a myriad of different subjective elements within the personal domain of the individual. Many individuals never experience PTSD or other trauma disorders (Cimolai et. al., 2021). Yet, for the smaller percentage that do develop trauma disorders such as PTSD, the long term healing can be a painful journey. Initially, most will experience denial, shock and disbelief. Some survivors will experience intrusive thoughts, dreams, nightmares, sleep disturbances as well as irritability and trouble concentrating. Others will manifest symptoms of hypervigilance as well as hyperarousal (Cimolai et. al., 2021). Physiological issues can also manifest with irritable bowel, stomach, and headaches.
Of course, those who suffer from PTSD, will continue to experience hypervigilance and hyperarousal which can be easily triggered by similar sights, sounds, scents, or places. In these cases, the traumatic memory has been unable to properly processed leaving unhealed trauma in the brain. Death imprint and survival guilt can all haunt individuals. Some may feel embarrassed or angry how they reacted to a life and death situation, while others may feel guilt about surviving. All of these feelings and emotions coincide with acute, but also long term trauma issues. To learn more about Trauma Informed Care or PTSD, please review the links below:
Unfortunately, many individuals who survive mass shootings suffer in reduced academic levels following a shooting. Statistically, they academic test scores drop for up to 3 years, higher level of absenteeism manifest and less fruitful and fulfilling careers are a result. There is also a correlation with a higher rate of substance abuse (Cimolai et. al., 2021). In addition, SSRI prescriptions increase by 21% after a shooting (Levine & McKnight, 2024). For those who continue to suffer with PTSD due to trauma, many endure a very long process of counseling to help process the pain and suffering (Webber
Prevention
Local communities must always be prepared for disasters or mass casualty events. EMA directors work closely with local emergency services for planning and training, as well coordination with other state officials and federal aid. Many plans are derived from already existing plans with modifications to the particulars. Good plans help improve local capabilities, facilitate quicker responses and help increase effective integration with other levels of government (U.S. Department of Homeland Security, National Response Plan, December, 2004).
In addition, in particular schools, mandatory lockdown and evacuation drills are a unfortunate necessity in a dangerous world (Webber & Mascari, 2018). This includes planning, drills, social media alert systems, first aid training in hemorrhage control, as well as understanding when to instill run, hide or fight responses (Reeping, et al., 2020). Some schools, as well as businesses, have invested in security and armed guards. While this is less than ideal for an environment of learning, it has become a necessary evil. While schools and many areas are gun free zones, having particular qualified and assigned individuals with conceal carry credentials has become an option ((Webber & Mascari, 2018).
Individuals, students, teachers, co-workers, and all members of the community need to be alert and watching for suspicious activity. This involves not only identifying social withdraw, depression, or mental illness in others but also identifying odd behaviors (Webber & Mascari, 2018). For educators, there is an important need recognize poor dynamics of an individual in regards to family, schooling, social interaction and one’s personality (Webber & Mascari, 2018). It requires accepting the fact that while America and the world at large has a gun and violence problem, it also has a mental health problem. It involves identifying sources of entertainment, gaming, or social media that can provoke violent behavior with those experiencing mental issues. A strong response is also essential to bullying or cyber bullying of individuals (Webber & Mascari, 2018).
Prevention not only involves reporting or spotting bullying, but also looking for the signs of a potential violent reaction. Many signs manifest well beyond the event on social media. According to O’Connor, 30 percent of shootings prior to event include odd posts online or on the shooter’s social media (2025).
Finally, socially, government and communities must address mental health and gun laws. While mental health issues are the root of the problem, access to fire arms create the perfect storm and death. How fire arms are purchased, better mental health screening, and enforcement and application of existing laws are essential. Loopholes of any type need to be addressed. In regards to the power of the firearm remains a constitutional debate but common sense regulation is something any gun owner should support. Finally, holding those responsible for not properly locking their firearms or permitting access to firearms for individuals that pose a threat or maturity is a serious concern. Recent cases of shootings have held parents criminally responsible for their children’s actions. The recent verdict in the Crumbley case in Michigan illustrate how serious the government has become in ensuring parents keep their firearms out of reach of their children (Levenson, et al., 2024).
Conclusion
Mass casualty events can vary in details. Some are acts of terrorism with political agendas, others are criminal in nature such as gang warfare, but the most disturbing are domestic shooters with mental health issues. Understanding that America and many parts of the world have both a mental health crisis as well as a gun control problem are just the tip of the iceberg. How to prevent these events and how to better respond to them when they do occur are key points of discussion of communities, law enforcement and government agencies. It is important to remain diligent and look for the signs of mental health in issues that may lead to mass gun violence.
Additional AIHCP Blogs
Trauma and Dissociation. Click here
References
O’Connor, D., Lewis Jr., R., Jacome Jr., T., Joseph, B. & Magnotti, L. (2025). Dissecting the numbers: A detailed analysis of 23 years of mass shootings
across the United States. The American Journal of Surgery, 250, 116516. https://doi.org/10.1016/j.amjsurg.2025.116516
Webber, J. & Mascari, B. (Eds.) (2018). Disaster mental health counseling: A guide to preparing and responding (Fourth Edition). American Counseling Association.
Levine, P. & McKnight R. (2024). The consequences of high-fatality school shootings for surviving students. J Policy Anal Manage, 24(43), 1034–1056. DOI: 10.1002/pam.22579
Cimolai. V., Schmitz, J. & Bela Sood, A. (2021). Effects of mass shootings on the mental health of children and adolescents. Current Psychiatry Reports 21(23), 12. https://doi.org/10.1007/s11920-021-01222-2
Reddy, M. (2013). Profiling the mental health of mass shooters. Chicago Policy Review, 13(10) University of Chicago.
https://go.openathens.net/redirector/regent.edu?url=https://www.proquest.com/scholarly-journals/profiling-mental-health-mass-shooters/docview/1439357084/se-2?accountid=13479
Santa Clara County Public Health Department Advanced Practice Center (2004). Managing mass fatalities: A toolkit for planning. U.S. Department of Homeland Security, National Response Plan.
Reeping PM, Jacoby S, Rajan S, Branas CC. Rapid response to mass shootings: A review and recommendations (2020). Criminol Public Policy, 20(19):295–315.
https://doi.org/10.1111/1745-9133.12479
Additional Resources
James and Jennifer Crumbley, parents of Michigan school shooter, sentenced to 10 to 15 years in prison for manslaughter. CNN. Click here
