These 5 states have the highest risk of a mass school shooting, according to a new study

Mass school shootings in the U.S. are an ongoing tragedy. This year has already seen several, and included the deaths of three children and three staffers at the Covenant School in Nashville. Last year saw the deaths of 19 children and two adults at a shooting at Robb Elementary School in Uvalde, Texas.

While mass shootings at schools are largely unpredictable, new research is attempting to give people insight into how likely their state is to experience one of these devastating incidents.

“We all read and watch the news and see more examples of horrific mass shootings,” study co-author Cameron MacKenzie, associate professor of industrial engineering at Iowa State University, tells Yahoo Life.“Knowing the national risk of a mass shooting and the local risk of a mass shooting at a specific location can help inform policymakers and decision makers about the real threat of a mass shooting and to what extent we should allocate resources and take measures to mitigate the risk of mass shootings.”

How likely are you to have a mass shooting in your state? Here’s what the research found, as well as what it means for you.

What the study says

The study suggests that states with the greatest risk of mass shootings — defined as an incident where four or more victims are killed by a gun in a public place — are the ones with the largest populations.

What are the key findings?

For the study, researchers from Iowa State University used statistical methods and computer simulations on a database of mass shootings that have been recorded from 1966 to 2020 by the Violence Project. The nonprofit found that the U.S. has experienced 173 mass shootings during that time period, with at least one a year since 1966.

With that data, the researchers used different models to try to predict and calculate the expected number of mass shootings in each state, the probability that at least one would happen in each state in a year and potential locations for those shootings.

The researchers found that the states with the largest risk of a mass shooting were the ones with the largest populations — California, Texas, Florida, New York and Pennsylvania. Those five states made up almost 50% of the predicted mass shootings. The researchers also noted that certain states, including Iowa and Delaware, have never had a mass shooting.

Based on calculations, the risk of a mass shooting at the largest California high school is about 10 times higher than the risk at the largest Iowa high school. Also worth noting: The number of mass shootings in the U.S. has increased by about one shooting every 10 years since the 1970s.

What experts think

MacKenzie says the findings reveal there are an average of six mass shootings in the U.S. each year. "This translates to a very, very small chance that a specific school will experience a mass shooting — an annual chance between one in 100,000 and one in 10 million," he says. "This does not mean there is no risk, but it is very small."

But MacKenzie acknowledges that the definition of “mass shooting” can vary. “When most media outlets report numbers on mass shootings, they seem to frequently rely on a definition used by the Gun Violence Archive (GVA). GVA defines a mass shooting as four or more people shot — injured or killed — not including the shooter, at any location,” he says. “According to this broader definition, there are more than 600 mass shootings in the United States in a year.”

These shootings typically involve the targeting of specific people (such as after an argument), he says. "The lives lost from these types of shootings are tragic, and we should work to prevent these types of shootings, but shootings that target specific individuals are qualitatively different than the stricter definition of mass shootings used in our study," MacKenzie explains.

Mass shootings in any location are “exceedingly rare,” Jaclyn Schildkraut, executive director of Regional Gun Violence Research Consortium at the Rockefeller Institute of Government, tells Yahoo Life. “When considering all offenses known to law enforcement, homicides in general make up less than 1% of these crimes," she says. "Mass shootings make up less than 1% of this 1%.”

Schildkraut says that mass shootings in schools “are even rarer,” adding, “They typically account, on average, for about 25% of all mass shootings occurring between 1966 and 2022.”

Why it matters

MacKenzie says the study findings should help make parents a little less worried about their child being a victim of a school mass shooting, but also acknowledges that it isn’t necessarily that simple. “Our results show that it is very, very unlikely that a K-12 student will attend a school during a mass shooting,” he says. “If you are a parent of a child at a school that experiences a mass shooting, explaining that the school was extremely unlucky provides no comfort.”

Schildkraut agrees. “It is incredibly important for parents to understand that school shootings are incredibly and statistically rare,” she says. “We do know from all of the school shootings that have happened, particularly when highlighted in the news — Columbine, Sandy Hook, Parkland, Uvalde — that these incidents are possible, however rare they may be, which is why it is important for schools to have comprehensive emergency response plans that include practices for lockdowns but are not solely focused on active shooter events. Schools should plan and prepare for every bad day they may have, not only the worst day.”

MacKenzie says that parents “should understand that mass shootings are very low probability but high consequence events.” He adds, “Taking precautions is reasonable, but we should not over-exaggerate the threat or live in fear that our children will experience such a horrific event.”