According to Nirvi Shah, writing for EdWeek:

A panel of school safety, climate, and security experts quizzed by a House committee today largely agreed that schools need more counselors, better communication between adults on campus and students, and additional, thoughtful emergency planning.

One thing they don't need, according to the experts: Teachers carrying guns to class.

Shah quotes David Osher of the American Institutes for Research, who she calls a "school climate guru": "The real challenge in schools is not the low-incidence and very traumatic events we want to prevent. It's low-level aggression that takes place persistently."

Shah points out that "Combating that, and ultimately preventing more serious events, begins with forming trusting relationships between students and adults, especially school resource officers and counselors." [emphasis added]

The complete article can be found here.