There are four words to remember when responding during an active shooter event: detection, deterrence delay, and defeat.

The Four Ds of Active Shooter Response

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The standard response time for emergency and rescue services in the United States is on average 4 to 11 minutes. That’s less time than it takes to microwave a potato — and yet it still isn’t fast enough in an active shooter event. Knowing the four Ds of active shooter response could make all the difference when the clock is ticking and lives are at stake.

There are four words to remember when responding during an active shooter event: detection, deterrence delay, and defeat.

Active Shooter Events Are Over In Minutes

According to a 2013 FBI study, almost 70% of gun-related active assailant events last just five minutes. A third of those last less than two minutes.

Consider the 2017 Las Vegas shooting near the Mandalay Bay Hotel. In 10 minutes a 64-year-old gunman fired 1,100 rounds into the crowd gathered for a country music concert. He killed 58 people and injured over 800. Or consider the February 2018 Parkland school shooting. Less than seven minutes elapsed from the time the alleged shooter uncased his rifle to the time he dropped it and left school grounds. At the end of that time he had killed, critically wounded, or injured 34 people. Only 17 of those injured ultimately survived.

More recently there was the April 3rd shooting at the San Bruno (California) offices of YouTube. According to most reports, just two minutes elapsed between the first 911 call and police arriving on scene. That is a stellar response time.

First Responder Time To Active Shooter Events

Nonetheless, when officers arrived at YouTube, the alleged shooter had already injured three and taken her own life. “Four minutes is not slow,” explains Mike Rehfeld, Founder, President, and CEO of Intrusion Technologies, “It’s just not effective in reducing casualties. If we’re going to reduce the casualties, we have to provide some sort of protective mechanism within the first seconds of an event.”

Drawing on their nearly 100 years of law enforcement and public safety experience (including Rehfeld’s own 32-year career in law enforcement and the fire service), the team at Intrusion Technologies has defined four aspects of active shooter mitigation, the so-called “Four Ds.

The Four Ds Of Active Shooter Response

  • Detection — Quickly determine that an attack is underway (or imminent).
  • Deterrence — Prevent the attack.
  • Delay — Slow the attacker’s progress; every second saves lives.
  • Defeat — Neutralize the attacker.

It surprises many to learn that Detection is even an issue. We like to think that we’re able to immediately recognize threats to our safety. In general, that is simply not the case. As Rehfeld explains, “One of the very common themes across all of these events, all the way back to the Columbine shooting, is that people did not recognize the gun fire as gun fire. They thought it was everything but gunfire. If it takes 30 seconds to a minute for a human to recognize the sounds of a direct-threat event, then that slows down their reaction time to protect themselves or other people.”

When asked specifically about the YouTube attack, Rehfeld noted, “My first thought was that these events can be stopped within seconds, and in doing so reduce the casualties as close to zero as technology allows.” The stumbling block? “Human reaction to these events is way too slow to effectively reduce the consequences.”

As the FBI concluded in its 2013 report: “Even when law enforcement was present or able to respond within minutes, civilians often had to make life and death decisions, and, therefore, should be engaged [in advance] in training and discussions on decisions they may face” during active shooter events.

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The AIMS Active Intruder Mitigation System

Intrusion Technologies has created a comprehensive solution AIMS, their flagship active intruder mitigation system.

AIMS has three alert levels. The lowest of these is Level 3, also called “situational awareness alert.” During a Level 3 situation the system alerts building occupants that there is reason for concern without disrupting their workday. A subset of the building occupants (like security and administration) receive automated mass notification messages explaining the situation. Most importantly, the magnetic holdbacks on open doors release, allowing the doors to close (but remain unlocked). If the situation should escalate, doors can be secured with 1200-pound magnetic locks without any delay, and occupants are already alert to the possibility of an evolving threat.

At Level 2 — the “local-area lockdown” alert — all affected building occupants receive automated mass notification messages. Additionally, all of the doors close and magnetically lock. Building occupants can freely exit, but no one (save law enforcement, who have override capabilities) can enter.

At Level 1 the building is on full alert. There are multiple alerts, including sirens and area-specific voice instructions, as well as mass notification via email, text message, etc. Doors release and lock, safe rooms engage, and a computer-aided dispatch dump is sent to first responders. Depending on the overall system design, law enforcement can also begin receiving direct feeds from building security cameras at that time, and even flood common areas with fog to confuse attackers. In a Level 1 alert fire alarm pulls are also disabled — a best-practice identified by many experts, including Lencore’s David Smith. This prevents attackers from using the fire alarms to trick people into leaving safety.

Automated Detection Coupled With Training

Most importantly, Intrusion Technologies built the AIMS platform to address the “detection problem.” AIMS doesn’t just activate when someone hits a panic button. Much as a fire signaling system can detect smoke or heat before you can, the AIMS system can sense threats. For example, the system can detect a gunshot. When that happens, AIMS automatically goes to Level 1 lockdown, alerting law enforcement and guiding building occupants to safety.

But locking doors takes time. Every released door needs to ease shut before it can engage. This creates a seconds-long gap during which an assailant might dash forward and gain access to more of the building. Since most attacks are preceded by high emotion, AIMS also watches for angry voices. Depending on the level of aggression it senses, AIMS will automatically advance to Level 3 or Level 2 alert. This shaves off critical seconds from the time it takes to lockdown and call in law enforcement (if needed).

Mike Rehfeld emphasizes that, even with advanced technology, there is no single drop-in solution. “We developed a comprehensive solution that addresses the Four Ds, not just a part of a solution. If you take a violent event and break it down into its parts, each of those parts — detection, cameras, lockdown, notification, responder friendly, training — all have to be part of that solution. If you leave out one of those important parts, you don’t have a complete solution. That’s why we train building users in threat reaction, so they know the best practices within their situation.”

Every Second Saves Lives

“Every second saves lives,” says Mike Rehfeld, “so our goal has been to reduce this response timeline as close to zero as we can get. With our current technology, we can get that down to as low as four seconds. Just four seconds that an attacker has access to potential victims. As we move forward, with advances in detection and AI technology, we see it as likely that we’ll begin to be able to stop these attacks even sooner, even before they start.”

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