By Matt Petrillo

MULLICA HILL, N.J. (CBS) — Following the Texas elementary school shooting that killed 19 children and two teachers, Eyewitness News got an up-close and exclusive look at security measures inside an elementary school in South Jersey.

CBS3’s tour of Harrison Elementary School came hours after the American flag was lowered to half-staff. It’s in honor of the Uvalde, Texas, victims. One of the most recent upgrades came after the Parkland High School massacre four years ago.

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“School safety has always been a top priority,” Harrison Township School District Superintendent Dr. Missy Peretti said.

Visitors can only get into Harrison Elementary School in Gloucester County through a front entrance by first speaking through an intercom and then having to wait in a dual-locked lobby.

“So no visitor, even when they ring in, can go all the way into the building,” Peretti said.

The Harrison School District superintendent says these doors were made more secure roughly four years ago, shortly after the Parkland High School massacre in South Florida where 17 students and staff lost their lives.

Also part of the security plan, emergency drills are twice a month, those include active shooter drills.

“Lights are shut off,” Peretti said.

Doors are then locked, and the blinds come down.

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“This is on every door so that nobody can see through the window,” Peretti said.

Harrison Elementary School also has multiple school resource officers, plus panic buttons that connect immediately to the police, and every teacher is trained to know how to put the school on lockdown.

“If a teacher sees someone that is out of place, they have the ability to go on the intercom system to lock down our building because they would be the first line of defense,” Peretti said.

The Harrison School District superintendent also showed CBS3 the back of the elementary school, where doors are locked. You cannot get in without a key.

That was not the case in the Texas school shooting. Police say the gunman got in through an unlocked back door.

“No one thinks this would happen in our town, so we’re no different,” Peretti said. “And I think that’s the hardest part to really digest.”

Gov. Phil Murphy increased the police presence at schools across the Garden State on Wednesday after the shooting, though there was no known threat to any schools.

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Many districts will continue to have this increased presence through the end of the school year.