Justin Rivard with the JustinKase
Teenager Justin Rivard believes his door locking invention can save lives during school shootings. YouTube/KARE 11

A high school senior in the United States believes his invention is the answer to saving lives in school shootings.

Justin Rivard, of Somerset High School in Wisconsin, has been working on the "JustinKase" since he was 15 (two years ago). The JustinKase is a metal device that can slide beneath the door of a room to latch on to the the frame on the other side. The door is then nearly impossible for a shooter to open.

Speaking to KARE 11 news in Minnesota, Justin said it takes just a matter of seconds to put in place. "You can lock a door with a lock, it can get shot out. You can lock a door with this, it can't get out. You can't get around it."

Somerset High School principal Shannon Donnelly has already ordered 50 for the school. "He truly believes that this device will save lives," Donnelly said. "We immediately, within a week of having these, went through an entire drill, all throughout the building, really walking through students and staff."

Justin told KARE he hopes schools will never have to use it. It is designed to buy students and staff time until police arrive at the school. The JustinKase sells for $95.

"While school shootings like Sandy Hook, Columbine, and others gain headlines, school districts around the country experience dozens of lockdowns due to various security concerns," the JustinKase website reads.

"Nobody expects an emergency but smart people plan for them and JustinKase is there to help. Seconds count."

Justin invented the device at school, during a metal works class. He is leaving control of the business to his father once he finishes school so that he can go and "serve his country".

The device fits under the door from the inside of a room and latches onto the frame from the outside. YouTube/KARE 11