In 2010, law enforcement training emphasized a singular priority during an Active Shooter/Mass Casualty Incident: while active killing is occurring, bypass the wounded and neutralize the threat. That principle remains sound.

However, the follow-on actions often created unintended consequences.

Once the threat was down, officers were taught to continue clearing the structure in search of additional suspects—often without any stimulussuch as ongoing gunfire, new victims, or actionable intelligence. This led to a critical problem: resources were being committed to chasing unknown threats instead of saving known lives.

Every minute spent searching for a non-existent secondary suspect is a minute lost for victims who could survive with immediate intervention.

Current data reinforces this reality:

• ~97.5% of      active shooter events involve a single assailant 
• When multiple attackers are      involved, they are typically co-located, not dispersed throughout      the structure 
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Even in today’s environment—where concern exists for complex coordinated attacks (e.g., Mumbai-style scenarios)—clearing without stimulus introduces unnecessary risk. Officers may expose themselves to ambush while simultaneously delaying life-saving care.

This is where doctrine has evolved.

👉 If active killing is ongoing: Stop the Killing

👉 If active killing has ceased: Stop the Dying

This is not just a tactical shift—it is a command decision.

Recognizing the transition point and reallocating resources accordingly is what saves lives.