Students lined up at Upper Darby High School Dec. 4 for their first Evolv weapons detector walk-through, writes Maddie Hanna for The Philadelphia Inquirer.

By the time the students were finished passing through the new Evolv system, a pair of brass knuckles and a knife were spotted.

The AI that runs the Evolv system wasn’t even supposed to identify knives, said School Superintendent Dan McGarry, but he’s glad it did.

“We’re looking for guns,” he said.

The weapons security system was approved in September and installed after a loaded gun and an AR-style magazine were found at the high school during the first few weeks of school.

The move to install the weapons detection system costing the district $1 million over four years, received largely positive support from parents and the community.

The detectors, installed at the two middle schools and the high school, screen 4,000 students daily just at the high school alone.

By day two, officials said, the detectors were running smoother than expected, with all students passing through in 15 minutes.

High school principal Craig Parkinson said the vibe with the new technology has been positive.

“Students and staff like it,” Parkinson said.

Read more about how the Evolv system is working in Upper Darby schools in The Philadelphia Inquirer.