74 people have been killed or injured by guns at American schools this year

On Monday, three children and three staff members were fatally shot at the Covenant School in Nashville, which one expert describes as part of an "astronomical increase" in violence on school campuses in recent years.

There is no universal definition of a school shooting, explains Jillian Peterson, an associate professor of criminology and the president of the Violence Project, a non-profit research center.

"In my research, we focus on school mass shootings, which is a really narrow definition where somebody comes, is heavily armed, fires indiscriminately, and kills four or more people," she said.

The federal government currently does not track the specifics of shootings that occur in schools. And while Peterson says they have been relatively rare over the past few years, there has been an increase in frequency in overall violence on school campuses that is undeniable, regardless of the methodology involved in data collection.

"I used to say mass shootings are rare, school shootings are rare," Peterson said. "But it's hard to keep saying that, you know, even though statistically they are, it's getting harder to convince parents of that."

In 2022, there were more school shootings than in any year since 1999, according to the Washington Post's tracker.

By the Post's measure, the total for 2022 was 46 — but that is only during school hours.

If the parameters are widened to incidents after school, over the weekend, when a gun is brandished, fired, or when a bullet hits school property, that number leaps to 303 in 2022, according to the K-12 School Shooting Database, an independent research project.

The K-12 database definition also includes gang shootings, suicides, and accidents."This information is recorded to document the full scope of gun violence on school campuses," its website reads.

Peterson says that the database, which works in partnership with the Violence Project, demonstrates how community violence is bleeding into schools.

"That includes things motivated by interpersonal conflicts, domestic violence, retaliation, all of those things, fights that escalate because people are armed," she said.

In 2023, the K-12 database has recorded 89 gun-related incidents at a school so far, nearly one for every day this year.It finds that, including the deaths in Nashville this week, there have been 74 people killed or injured this year alone, not including the shooters. That includes 18 people fatally shot, and 56 more who were injured.

In 2020, firearms overtook auto accidents as the leading cause of death for children between the ages of 1 to 19.

According to the Gun Violence Archive, there have been 130 mass shootings in the U.S. in 2023. That definition includes four or more people shot or killed, not including the shooter.

Another category that Peterson says has seen a surge in frequency are threats of violence made, online or in person, which can be difficult for schools to track and manage.

Peterson, who is the parent of three elementary school-aged children says that community engagement can be vital in managing those threats, and preventing more tragedies.

"One thing we do know is that the most likely perpetrator of a school shooting is a child in that school. It is a classmate," she said. "It's somebody that is getting seen every day. And so they are likely to tell their classmates that they're planning on it. They give out warning signs."

Part of Peterson's research includes studying the life histories and pathways to violence for the perpetrators. And in many cases, they follow the same steps, including telling others about their plans, a term called "leakage."

Because of this, Peterson says giving students a clear pathway to sharing any suspicions of these warning signs is crucial.

"The best thing we can do is actually just have really good relationships with our kids, making sure that they feel comfortable reporting," she said.

She also says schools need to take steps to have crisis intervention teams, suicide prevention teams, school based mental health, and anonymous reporting systems to give at-risk students resources, in addition to campaigning for improved gun safety among parents that are firearms owners.

"I think pushing for safe storage campaigns [is key] because the majority of school shooters are taking guns from home. So the more we can help parents who own firearms make sure those are secured, that's helpful," she added. [Copyright 2023 NPR]