Do you trust the 21 foot rule

The so-called “Tueller Rule” is widely misunderstood. It is not a rule, a law, or a justification for deadly force. It is simply a demonstration of timing.

What it shows is this:

If an average person with a knife starts approximately 21 feet away and charges at an average speed, and you have an average ability to recognize the threat, draw your firearm, and fire accurate rounds center mass—you are likely going to get stabbed.

That’s it.

It does not mean:

• You are safe beyond 21 feet 
• You are doomed within 21 feet      
• You are justified in using      deadly force at 21 feet 

It is not about legal justification. It is about human performance and reaction time under stress.

The Critical Reality Most People Miss

Even if you successfully draw and fire center mass, the threat does not stop immediately.

• A person who has been shot      center mass can still: 
  • Continue forward momentum 
  • Deliver multiple fatal       strikes 
  • Function for seconds to       minutes 

At contact distance, seconds are everything.

So the likely outcome in that scenario is not:

“Officer shoots suspect and survives”

It is:“Both individuals are mortally wounded”

What the Tueller Concept Should Actually Teach

The real lesson is not about when to shoot—it’s about how to avoid being in that position in the first place.

It should reinforce:

• Distance is      life 
• Movement      beats reaction 
• Positioning      matters more than speed 
• Time must be      created, not assumed 

Because if you are standing flat-footed, reacting to a sudden knife charge inside that distance, you are already behind the curve.

Operational Takeaways for Law Enforcement

• Do not anchor yourself at a      fixed distance 
• Create angles, barriers, and      obstacles 
• Move early—not after the      suspect commits 
• Use commands, positioning,      and coordination to control space 
• Understand that firearms are      not instantaneous stop mechanisms 

Bottom Line

The Tueller Drill does not tell you when to shoot.

It tells you how fast you can lose.

And if your plan begins at 21 feet with a reactive draw, your outcome is already compromised.  

In an active shooter / mass casualty incident, command doesn’t start at the top—it starts inside with the first officers and then transitions outward in phases. This is very different from Fire/EMS, where command is established from the exterior on arrival.