What officers really need to know about the 21-foot kill zone

Each circustance is unique and while action/reaction time is vital to the equation, there are many other pieces for consideration when using deadly force


The Police Executive Research Forum  recently released their report: Re-engineering Training on Police Use of Force. The document contains an in-depth discussion of Lieutenant Dennis Tueller’s 21-foot drill, often erroneously cited as the “21-foot rule.”

The comments within the document should be alarming. Many national police executives opine that the 30-year-old magazine article written by Tueller has been misinterpreted as creating a “21-foot kill zone.”

Facts on Tueller’s 21-foot Drill
Below are the facts from the original article (which you can read in full here):

    An armed (edged or blunt weapon) suspect can cross 21 feet in about 1.5 seconds
    An officer may draw from the holster and fire 2 rounds in 1 - 1.5 seconds
    Those first rounds may not stop the threat

Tueller’s original recommendations include developing tactical awareness to spot danger signs early, spotting danger signs early will “probably” allow an officer to avoid the confrontation altogether, a tactical withdrawal may be your best bet and, finally, if an attack is imminent, move to cover, draw your weapon and plan the next move.

The bottom line is that Tueller identified a danger area of 21 feet for a holstered officer and made officer safety recommendations consistent with those contained in the PERF report. More importantly, Tueller’s drill is the foundation for some of today’s action/reaction time research, which should be correctly applied to train officers to increase distance (when possible) in myriad situations. The distance increase is likely beyond what officers may have originally felt was sufficient. 

Submitted as evidence are the following suspect-movement time studies:

Research on officer-movement time 
In addition to the above studies, a study by Alexander Jason revealed that officers draw (multiple holster types) and fire one round from the holster at an average of 1.5 seconds.* A study by the Force Science Institute suggested that officers draw and fire one round from the Level III holster at an average of 2.0 seconds*, and findings from another study by them suggest that officers can fire from a high or low ready position at an average of .83s.* Finally, research by FLETC / Bruce Siddle revealed that officers reacting to a threat can fire from a high ready position at an average of one second with 30 percent accuracy. The accuracy increased to 90 percent with a response time of 2.3 seconds.**

What does it all mean?
The evidence listed here is not to suggest an expansion of any type of perceived kill zone or area where a use of deadly force becomes automatic.*** It does suggest that officers should be trained to increase distances beyond 21-feet when facing an armed suspect when possible.

My recommendation is to slow down and use good tactical decision making based on observation from a distance. Understanding how quickly a situation can go bad is a vital officer safety tool that can save lives on both sides of the badge (see video below). 

Ultimately, each circumstance is unique and while action/reaction time is vital to the equation there are many other pieces for consideration: equipment, competency, accuracy, stress, environment, subject capabilities, officer capabilities, and the fact that a bullet does not always immediately stop threats. 

A use of deadly force against a suspect with a knife or blunt force weapon will be evaluated on all the details and circumstances known or reasonably known to the officer at the moment the time was used. It is not simply the distance an officer was standing from a threat. 

While the evidence for this opinion is anecdotal at best, this article is intended to clarify any misinterpretation. Add your thoughts in the comment section below. 

Be safe. Be vigilant. 


*Laboratory result based on sound stimulus. Officer already knows the response and only has to react without the decision making time of a real world encounter.
**Laboratory result based on Force Options Simulator. 
***There is no such thing as a kill zone in Law Enforcement. 

Request product info from top Police Firearms companies

Thank You!

By submitting your information, you agree to be contacted by the selected vendor(s).

Join the discussion

Brand Focus

Sponsored content
2017 JAG Guide for Firearms Training Programs

2017 JAG Guide for Firearms Training Programs

Our PoliceGrantsHelp staff provide the tips you need to win firearms training grants

Copyright © 2018 PoliceOne.com. All rights reserved.