Mary Ford, the chief marketing officer for Centegix, said Charlotte schools had been pilot-testing the alert system and that the company addressed issues that arose. The company has delivered more than 100,000 alerts, she added, and worked with nearly 200 school districts, retaining 99 percent of those customers, with the exception being Charlotte-Mecklenburg.
This spring, after an uptick in the number of guns confiscated from students, Charlotte-Mecklenburg schools introduced a different security system: walk-through weapon scanners that cost $5 million for 52 scanners at 21 high schools.
The scanners come from Evolv Technology, a Massachusetts start-up that said it had used machine learning to train its system to recognize magnetic fields around guns and other concealed weapons. “No stopping is required,” the company’s website says, “no emptying pockets or removing bags.”
But common student items have routinely set off the Evolv scanners, among them laptops, umbrellas, three-ring binders, spiral-bound notebooks and metal water bottles.
In a how-to video about the scanners posted on YouTube in April, Matthew Garcia, dean of students at Charlotte-Mecklenburg’s Butler High School, recommended that students remove those objects from their bags and carry them. Then Mr. Garcia showed students how to avoid triggering the system — by walking through an Evolv scanner in the school lobby holding a laptop with his arms stretched above his head.