DOUGLAS COUNTY, Colo. (KDVR) — Inside Mountain Vista High School in Highlands Ranch, Nicholas Dimercurio is always looking for his next great invention.

The senior has spent more time than he can count inside the school’s computer lab, tinkering with various ideas on a 3D printer. But earlier this school year, he received a request from an unexpected source: school resource officer Jeff Cislo.

“We realized there was a situation where deputies went through the door, the doors locked behind them, and there was no other way for them to come through,” Cislo said. “Clearly, these guys are way smarter than I am, so we came to Nick and said here’s our problem.”

Dimercurio went to work, producing prototype after prototype until the perfect one was built. 

The device quickly clips onto the outside of a door, preventing it from shutting. It’s small enough to be held in a police vest, and it’s lightweight and durable.

“It’s very important to me to think that something that I made inside of a school, to make something that keeps school safer, is very important,” Dimercurio said.

The Douglas County Sheriff’s Office has purchased dozens of additional items for other schools in the district.

Dimercurio is now working on his next project, a 3D-printable device to keep doors closed during school emergencies.

He graduates this spring before moving on to pursue an electrical engineering degree at Wichita State University.