Report finds school attacks are preventable "when communities identify warning signs and intervene"

Paying attention to warning signs and early intervention could be the difference between life and death for students.

A new report released by the Secret Service found that the key to preventing school attacks is early intervention by someone close to a student possibly planning violence.

The agency's National Threat Assessment Center analyzed nearly 70 disrupted school plots that were reported and averted between 2006 and 2018.

Tony Montalto lost his daughter, Gina, in 2018 when a former student killed 17 people and wounded 17 more at Marjory Stoneman Douglas High School in Parkland, Florida.

"Targeted school attacks frequently occur after we've had an absence. We know that COVID-19 is giving many students and schools the longest break in attendance they've ever had," Montalto told CBS News' Catherine Herridge.

With millions of students learning virtually and not in the classroom, some have lost their support network and mental health services.

"Some students, sadly, have not been in a nurturing and comfortable environment through the crisis as they learn from home," Montalto said.

The report, "Averting Targeted School Violence: A U.S. Secret Service Analysis of Plots Against Schools," found that students who plotted attacks shared many similarities with students who carried out violent attacks.

The students who plotted the attacks had "histories of school discipline and contact with law enforcement," they experienced "bullying or had mental health issues" and "used drugs or alcohol."

The report concluded, "School violence is preventable when communities identify warning signs and intervene."

Dr. Lina Alathari said that classmates were among the first to observe the warning signs.

"In this report, we've seen that students were the most positioned to come forward with this information," Alathari said.

The Secret Service analysis of plots against schools began after the 1999 Columbine shooting. Alathari said the attacks that were studied "in averting targeted school violence were really serious in nature."

"If you look at how far they got in their planning and the situation, this really could have presented serious harm," she said.

The Parkland shooter had a long history of emotional and disciplinary problems. Montalto is now president of Stand with Parkland, a group pushing for school safety and gun reform. He said a lot of warning signs were missed when it came to the Parkland shooter.

"Yes, many warning signs were missed. There were over 40 interactions with him and the local law enforcement. Everybody knew what a danger he was," he said.

The report identified other concerning behaviors, including an interest in violent or hate-filled topics and a fixation on mass shootings like Columbine.

Montalto said his daughter would have been graduating, part of the class of 2021. Their family has channeled its grief into action.

"It doesn't lessen the pain, but it allows us an avenue to work through and something to work towards rather than possibly dwell in our grief, constantly," he said.