tragedy, a deeper look at school security and what it will take to reassure parents their kids are safe in the classroom. Alex perez takes us inside one school sparing no expense for safety. Reporter:... See More
tragedy, a deeper look at school security and what it will take to reassure parents their kids are safe in the classroom. Alex perez takes us inside one school sparing no expense for safety. Reporter: The security measures at middleton elementary school in suburban chicago begin the moment you step foot on campus, with this camera-equipped doorbell. The visitor rings the doorbell. And the person inside can see us. They can see you. They can see what kind of mood you're in. If you're angry. Reporter: Once in, you can only get as far as the entryway. How are you? The front desk then takes my i.D., Scans it and performs an instant background check, using a security system called raptor, one that has already spread to 8,000 schools across the country. After you pass a second set of locked doors and enter the school, your every move is watched. On monitors in the front office, and by administrators on their smartphones. They have invested more than $175,000 over the last two years, beefing up security at the three schools that make up this tiny district in skokie, illinois. I don't know that there's too big a price tag on keeping your kids as safe as they can be. Reporter: Protection is key. M doors open inwand and ck from the inside. Eliminating the need to step out of the room if there's a threat in the hallway. Every measure of security counts. Like having cameras spread across the school. Even barriers to stop cars from getting too close. Another way to protect the school from every angle. All of these security measures buy you time. Every second counts. Reporter: When seconds mean precious, young lives like these fourth graders, she says the extra security is worth it. Everything we are have to do, we have to do. Reporter: And this school district isn't done yet. After sandy hook, they're also considering installing bullet-resistant glass. The truth of it, what we cannot afford is a terrible incident. Reporter: For "good morning america," alex perez, abc news, chicago. We're going to stay on top of all of these solutions.
This transcript has been automatically generated and may not be 100% accurate.