Fox said, however, some policy changes aimed at decreasing school shootings and gun violence in general certainly have merit. Banning bump stocks and raising the age of purchase for assault rifles from 18 to 21 are good ideas, and may lead to a decrease in overall gun violence, he said. But he doesn’t believe these measures will prevent school shootings. “The thing to remember is that these are extremely rare events, and no matter what you can come up with to prevent it, the shooter will have a workaround,” Fox said, adding that over the past 35 years, there have been only five cases in which someone ages 18 to 20 used an assault rifle in a mass shooting.

Fridel said increasing mental health resources for students is another strategy that might improve school safety, calling this a critical need that has been historically overlooked. She also said that the U.S. is facing a desperate shortage of guidance counselors. In 2014-15, the student-to-school counselor ratio was 482-to-1, according to the American School Counselor Association, nearly twice the organization’s recommended ratio.

“You might have students in a very large school who are troubled but who are basically flying under the radar, because you have one guidance counselor for 400 students,” Fridel said.