When Security Layers Overlap: The Value of Integration and Redundancy
Integrated systems, overlapping capabilities and trained personnel help campuses maintain security when technology or infrastructure fails.
- By Jill Renihan
- September 21, 2026
When security professionals talk about designing campus security systems, they usually describe their approach as “layered.” Start at the perimeter, then progressively restrict, manage, and monitor access as you move deeper into the property. By the time anyone enters the most secure locations, they’ve passed through multiple layers of security.
Described this way, it’s natural to envision concentric circles, each with dedicated technologies performing specific tasks. But this is overly simplistic. At each layer, we rely on multiple technologies because no single system can do everything we need it to. Conversely, most of those technologies span multiple layers. Ideally, they work together, integrated as a unified ecosystem.
At this point, we’re all familiar with the benefits of integrated solutions. Information from one system informs and influences how other systems behave. For example, an access control event can trigger the display of video cameras within a Security Operations Center, or video detection of unruly crowds can trigger automated audio announcements to disperse and summon officers to the scene.
However, integration is only part of the equation. What’s often overlooked are the benefits of having different solutions performing overlapping functions.
Consider a building entrance that’s equipped with a modern video/audio intercom. That same entrance is also covered by a surveillance camera – possibly with audio capabilities. Why deploy both?
The intercom is positioned at face level and gives security personnel a view of the person that wouldn’t be possible from an overhead camera. The visitor can hold up their ID, have a direct conversation with an operator, and the operator can see if the photo ID appears to match the person requesting entry. The intercom may also have a built-in access control reader for credentialed employees – eliminating the need for a separate device.
A mounted surveillance camera with audio at that same entryway might technically allow security to screen visitors before admitting them, but not from the location or angle best suited to making an access decision. Nor would it provide the same all-in-one experience for credentialed users, as the intercom can. However, it is better equipped to perform other functions. For example, with edge analytics, it might be able to detect whether a person approaching the doorway is carrying a weapon. Or, during hours when that entrance is closed to the public, motion detection within the camera could trigger an automated announcement redirecting visitors and alerting security before they approach the door.
Within the same security layer, the intercom and surveillance camera capabilities overlap and complement each other.
Standalone emergency stations are another example of where redundant, integrated technologies are useful. Blue-light towers were once a staple on any campus, but with the ubiquity of mobile devices, some institutions have stopped investing in them – assuming students will use their phones in an emergency. Some campuses offer security apps to make it easy for students to call for help. They can quickly connect with an officer, report an incident, and request assistance. But just because students have these apps doesn’t mean emergency towers aren’t valuable.
In fact, even when phone apps are deployed, emergency towers can strengthen a response. When activated, they not only immediately establish two-way communication with security, but also share live video from the location. Integrated with other campus surveillance cameras, those images can give responding officers better situational awareness before they arrive. Flashing lights and loudspeakers can draw attention to the site, encourage a bad actor to flee, and let everyone nearby know they are under observation and help will be there soon.
Plus, you can’t always count on a cellphone. Campuses have dead zones. A phone may be inside a backpack or purse and difficult to access while fleeing an attacker. Its battery may be dead. Or it may have been left behind. That’s why redundancy isn’t just about having systems with overlapping capabilities. It means that when one system temporarily fails, other tools are in place to maintain security operations.
True redundancy must also include a human layer.
Technology can tell us a great deal about what is happening on a campus, but it doesn’t necessarily understand how to process that information in context. An access control system may report that a door is closed, for example, but a security officer performing rounds might discover that it never fully latched. Or a system might recognize that an employee has presented a valid credential, while somebody at the security desk notices that the employee entered the wrong PIN twice and appears unusually nervous. Those observations provide important context that technology alone can miss.
The human role becomes even more important as campuses use AI and analytics to automate more security functions. In an instant, analytics can process far more data than humans. However, once it identifies issues of concern, you still want humans in the loop to make any final determination about potential threats. Without that step, innocent people can suffer the consequences and the public’s trust can erode. For example, just last year a Maryland high-school student was handcuffed and searched on school grounds because AI mistook a crumpled Doritos bag in his hand for a gun. Security personnel at the school reviewed the AI alert and determined there was no weapon, but only after the school principal had alerted the police. The findings of that added layer of human review never reached the responding officers.
As that example demonstrates, having a human in the loop only works when the human knows what to do with the information they have. And just as we shouldn’t rely too much on any one technology, we shouldn’t rely on just one person. Security teams need redundancy. If an alert comes in, who receives it? When should it be escalated? Who gets notified? What policies govern the response? If the only person who knows the answer to those questions is out sick or on vacation, we’ve created another single point of failure.
This is particularly important on campuses where security teams are already stretched thin. Technology can help a limited number of people monitor more areas and process more information, but it shouldn’t become an excuse to eliminate the human resources needed to respond appropriately when something may require a response.
In addition, don’t make a crisis the first time in months that someone has to remember how to navigate a system or workflow. Whenever possible, emergency capabilities – like initiating a lockdown – should be integrated into tools the staff uses regularly, so the interface and basic operation are familiar when something goes wrong.
Campuses also need to prepare for situations where the problem isn’t a single malfunctioning device or application but the underlying infrastructure. I once worked at a large Florida school district that received its internet feed via a single cable – which a lawn mower accidentally severed. For 2 ½ days, everything went down, including phones, email, and much of the functionality of the district’s electronic security systems. Fortunately, we could still operate because the administration had planned for such a scenario. They had printed student lists and could fall back on manual procedures. All campuses should have a similar playbook ready and participate in periodic drills to test whether they truly have the manual redundancy they think they do. In fact, testing backup operations by temporarily throttling back the internet in a controlled manner isn’t a bad idea.
Ultimately, there’s no single answer to campus security, which is why integrated technologies are so important. Systems need to work together seamlessly, capabilities need to overlap, and people must remain an integral part of the process. Back that up with clear policies, regular training, and plans for when technology isn’t available, and you have multiple ways to identify a problem, respond to it, and keep your campus safe.