Keung Hui of the News & Observer has the details,

A new report looking at security in North Carolina schools is challenging the belief that putting more police officers in schools will make them safer.

The study of North Carolina middle schools found no relationship between increased funding for school resource officers and reduction in cases of reported school crimes. Kenneth Alonzo Anderson, the report’s author and an associate professor at Howard University, said legislators across the country should consider the findings before rushing to put more police officers in schools following mass acts of violence such as the school shooting incident in Parkland. Fla.

In some ways, the research findings are irrelevant.  For years, researchers have pointed out that various security measures in schools do little to keep kids safe from school shootings, for example.  But as long as parents believe that metal detectors, cameras, and school resource officers improve school safety, districts and states will pour money into them.

Regardless, the debate is far from settled.  As proponents of school resource officers point out, it is nearly impossible to know if the presence of resource officers discouraged or deterred potential acts of school crime and violence (because they are not reported).