Sensor Architecture Targets False Alarms in Active Threats

Security teams face severe operational tension when configuring active shooter protocols. They must balance the need for immediate emergency notifications against the operational cost of initiating false alerts. When deterrence measures trigger incorrectly, operators disrupt operations and risk alert fatigue. The underlying threat is real but comparatively rare: the FBI designated 24 active shooter incidents across the United States in 2024, down 50 percent from 48 the prior year, which raises the stakes on every false alert that pulls responders away from a genuine event. According to the U.S. Department of Justice's Office of Community Oriented Policing Services, 94 to 98 percent of alarm calls turn out to be false. This reality forces physical security administrators to seek smarter filtering systems that do not sacrifice response speed.

Bypassing software filtering

Rather than reviewing signals in a separate software layer, some operators deploy multi-factor hardware validation. This approach requires independent confirmation across distinct physical phenomena before an alert ever leaves the sensor.

"The short answer is that we do not treat false alarm filtering as a tradeoff against speed. The architecture is designed so that both happen simultaneously, at the sensor, before any alert is ever transmitted," Billy Borho, Director of Sales at Shooter Detection Systems, an indoor threat intelligence manufacturer, said in written responses to Security Guys News. "SDS sensors require independent confirmation across two distinct physical phenomena: acoustic muzzle blast and infrared muzzle flash. A gunshot produces both. The vast majority of environmental noise sources that generate false alerts in other systems produce one signal but not both, or produce neither in the specific combination the sensor requires. That means the sensor is not filtering after the fact."

Validation at the edge

Because the confirmation requirement rests within the edge processing architecture, the system bypasses human verification. If both acoustic and infrared signals are not independently validated, the hardware generates no alert. Operators can then automate downstream responses, configuring the platform to notify onsite personnel or push directly to emergency services.

According to the company, the United Kingdom's National Protective Security Authority conducted an 18-month installed environment test of the indoor platform and recorded a zero percent false alert rate over the full period. The system also holds SAFETY Act certification from the U.S. Department of Homeland Security, which requires high confidence in ongoing effectiveness before deployment in federal facilities.

Keeping humans in the loop

Despite advances in edge processing, a contrasting viewpoint maintains that fully automated emergency responses pose operational risks. Because incident responses like full lockdowns carry high consequences and are difficult to reverse, some operators prefer maintaining a human validation step. In this model, automation accelerates data collection and downstream communication while preserving human authority over the final decision.

"Everything upstream - the tools detecting a threat - needs to get the right information into a decision-maker's hands as fast as possible. That means consolidating signals from sensors, cameras, access control, and other systems into a single view, so nobody has to assemble the picture themselves under pressure," Terry Swanson, President and CEO of Singlewire Software, an emergency mass notification provider, previously told Security Guys News. "Everything downstream - the tools delivering the information to everyone else - is about acting on the decision immediately once it's made. All of that runs on executing pre-configured emergency action plans, workflows, device mapping, and notification paths. The judgment call ends up being the only step that isn't automated."

Multi-factor validation can reduce false alarms, but requiring both acoustic and infrared confirmation may also suppress a genuine alert if one signal is obstructed or not captured. With the FBI recording just 24 active shooter incidents in the United States in 2024, individual failures may be difficult to identify through routine operational data. A layered response can mitigate this risk by combining sensor outputs with cameras and access-control data, immediately notifying trained personnel and reserving irreversible actions, such as a full lockdown, for human authorization.