A school custodian is emerging as one of the heroes of the latest headline-grabbing school shooting.

On April 10, Edna Gamarro was outside the library at North Park Elementary School in San Bernardino, Calif. when she heard the distinctive sound of gunshots.

At that moment, a little boy was exiting the library. Gamarro quickly redirected the child back into the library and to safety.

“I was just telling him to go inside and he was like ‘why why’ and I was like don’t ask anything and I just pushed him in and went inside and told the librarian just keep him inside, just go to the back door,” Edna Gamarro said in an interview with CBSNews.com.

The boy’s mother credited Gamarro with saving his life.

Gamarro’s sharp ears and quick thinking made a difference in the San Bernardino school shooting.

Guardian, a gunshot detection system developed by Shooter Detection Systems, puts the same sharp ears and quick thinking throughout a facility. Guardian works by using acoustic and infrared sensors to instantly identify gunshots. The precise location of the gunshots is noted, and authorities are alerted immediately.

The Guardian system has the ability to dramatically reduce response times in active shooter situations. A recent independent live-fire study in a two million square foot facility reduced reporting and first-responder dispatch time from as much as 18 minutes to just five seconds. Warnings can also be instantly sent out to people in the facility and vicinity advising them to evacuate or take cover. This video demonstrates the basics of the system.

Interested in learning more? Register for our Live Fire event.

ECT Services will also be participating in the Kentucky School Plant Management Association conference and workshops this year, which will take place Oct. 18-19 at the Embassy Suites Hotel at 1801 Newtown Pike in Lexington.