This story originally aired on March 20, 2019.
John Lovett is a retired police officer and the school safety and security coordinator at the Saint Marys Area School District.
It's a typical day at the high school in Elk County, Pennsylvania, and students stream down the halls during a break.
Lovett's job is helping keep the students safe. As part of that, he carries a taser and a gun. And he helps train the schools on what to do in an emergency, including a possible intruder.