Most school shootings are not sudden events; they usually come with warning signs. A year prior to a 14-year-old being taken into custody for supposedly opening fire in his high school math class in Winder, Georgia, on September 4, 2024, resulting in the deaths of two teachers and two students, the authorities had visited his home. This was to look into several anonymous tips about online threats to carry out a school shooting. When questioned at age 13, he denied making the threats. His father informed the police about hunting guns in the house but insisted the boy did not have “unsupervised access” to them. On the day of the shooting, the FBI stated there was “no probable cause for an arrest” and that local law enforcement had “alerted local schools for continued monitoring of the subject.” A week before the shooting, teachers received special identification cards with panic buttons. Although these cards are credited with reducing the severity of the shooting, they could not prevent deaths.
This situation is similar to many others we, a sociologist and psychologist, have gathered over recent years as we examine the lives of mass shooters. It exemplifies a significant challenge for schools in preventing shootings: identifying and taking action on warning signs that school shooters often exhibit before they attack. According to our database of mass shootings in the United States since 1966, defined as events where four or more people were killed with guns in a public place without any link to underlying criminal activities like gangs or drugs, there have been 15 incidents at K-12 schools. The first of these happened in Stockton, California, in 1989. Seven of these school shootings occurred in the last ten years, including the second and third deadliest on record: Robb Elementary School in Uvalde, Texas, in 2022 with 21 fatalities, and Marjory Stoneman Douglas High School in Parkland, Florida, in 2018 with 17 fatalities.
The most deadly occurred in December 2012 when 20 children and six adult staff members were killed at Sandy Hook Elementary School in Newtown, Connecticut. In total, 138 people have died, and at least 177 have been injured in these attacks. The Columbine High School massacre in 1999 was initially viewed as a turning point in the U.S., as it was the worst school shooting in the country’s history at that time. Twenty-five years later, it ranks fourth in severity. Despite billions of dollars spent on school safety since Columbine, school shootings have become more common and more lethal. A gun goes off in an American school almost daily beyond the mass shootings that make headlines. Our research and numerous interviews with shooters, survivors, and first responders indicate that part of the issue lies with law enforcement and school officials. Influenced by myths and misinformation about Columbine, they lack understanding of mass school shooting trends to properly identify warning signs.
Most mass school shootings are committed by a lone gunman, with only two incidents—Columbine and the 1998 Westside Middle School shooting in Jonesboro, Arkansas—involving two shooters. Describing the perpetrators as “gunmen” is appropriate since all but one in our database were carried out by males. Those involved in executing the attacks averaged 18 years of age, with the youngest being 11 and the oldest 32. As minors, most shooters used guns borrowed or stolen from parents, caregivers, or other significant adults. Following every school shooting, there is often disbelief, with people saying, “we never thought something like this could happen in our community.”
Nonetheless, mass school shootings predominantly occur in small suburban or rural communities like Winder, Georgia, where the suspect is a 14-year-old student of the school. This is not surprising, as most shooters have a connection to the school they attack. In our database, 15 out of the 17 school shooters were current or former students. For many perpetrators, the shooting is meant to be a final act; most school mass shooters die during the attack. Of the 17 shooters in our database, eight were captured, while the rest died at the scene, nearly all by suicide—the exception being the Robb Elementary shooter in Uvalde, who was shot by police. Motivated by prior shooters, some perpetrators aspire for notoriety, but most school mass shooters are driven by despair and general anger.
Over 80% showed crisis signs before the shooting, including depression, mood swings, and noticeable behavioral changes. Importantly, over 90% revealed their plans to others in advance, sharing posts, messages, or videos that warned of their intentions. School shooters communicate their harmful plans ahead of time as a final, desperate plea for help. The key to stopping these tragedies is to recognize and immediately act on these warnings.
Even without sufficient evidence for arrest, investigators can monitor students and connect them to school or community services, such as peer-mentoring or mental health treatment. Simply penalizing threats increases violence risks by heightening grievances with the school. Meanwhile, reminding parents to secure firearms is crucial. Almost all shootings by minors can be avoided through safe firearm storage and adult accountability. When firearms are kept locked, unloaded, and stored separately from ammunition, it becomes much harder for someone to use them quickly in an attack.