A new analysis released by the U.S. Secret Service on Thursday found that most school shooters showed warning signs and that the tragedies could have been prevented. The study is based on 41 incidents of "targeted school violence" that took place in American schools from 2008 to 2017.
The report, from the Secret Service's National Threat Assessment Center, was created to help school officials and law enforcement officers prevent tragedies in schools across the country.
Many of the attackers were victims of bullying, had a history with law enforcement and "communicated their intentions" to carry out an attack. "In many cases, someone observed a threatening communication or behavior but did not act, either out of fear, not believing the attacker, misjudging the immediacy or location, or believing they had dissuaded the attacker," the study says.
There is no set profile of a student attacker or a profile for what kind of school gets targeted, the study said. Instead, attackers usually had multiple motives. That can include a grievance with classmates, issues with romantic relationships or a desire to commit suicide.
While some attackers experienced behavioral or developmental issues, all experienced stressors in the days or months leading up to the attack. For example, one 14-year-old student who shot a classmate had been punched and called names. But that attacker also had a history of bullying others.
"I think it's just that they get to a point where they can't take it anymore," Dr. Lina Alathari, chief of the U.S. Secret Service Threat Assessment Center, told CBS News.
Ninety-four percent of attackers experienced a "home-life factor" that led to an incident.
"This could be related to family problems at home in terms of let's say domestic violence in the home. Drug use in the home among family members, divorce and separations," Alathari said.
Thursday's report finds most of the schools had some sort of security measure, like lockdown procedures or security cameras. Yet only 17% of the schools had a system in place for students to notify an official if they notice a peer in crisis.
Some of the behaviors students and staff should be aware of includes increased anger, an interest in weapons and violence, depression or isolation, self-harm or a sudden change in behavior. The majority of attackers even shared their intentions with someone else, either in person or online.
Jeff Pegues contributed to this report.