THE TUELLER DRILL BEST WAY OF SELF-DEFENcE
The 21 foot rule, also known as the Tueller Drill, is a concept in law enforcement and self-defence that illustrates the danger posed by an attacker armed with a melee weapon (like a knife) at close range.
Origin:
Created by Lt. Dennis Tueller of the Salt Lake City Police Department in the early 1980s.
Tueller timed how quickly an average person could cover 21 feet (about 6.4 meters) — it was roughly 1.5 seconds.
This is about the same amount of time it takes a trained officer to draw and fire a weapon.
Key Idea:
If an assailant with a knife is within 21 feet, they can potentially reach and stab a person before that person can draw and accurately fire a handgun in self-defence.
Implications:
Used in law enforcement training to emphasize reaction time, situational awareness, and appropriate use-of-force decisions.
It has been cited in use-of-force court cases and self-defence scenarios, though it’s not a legal standard — more of a training guideline.
Criticism:
Some argue it’s often misunderstood or misapplied to justify shootings.
Real-world variables (terrain, weapon readiness, reaction time, etc.) make the "21 feet" rule more of a general guideline than a strict measure.
The Tueller Drill is a widely used law enforcement training exercise developed to illustrate the reaction time gap between a firearm user and an attacker with a close-range weapon, like a knife.
🔹 What Is the Tueller Drill?
The Tueller Drill was created by Lt. Dennis Tueller in 1983. He wanted to answer a critical question:
"How close is too close for a suspect armed with a knife to pose a lethal threat to someone with a holstered firearm?"
He found that an average person can cover 21 feet in about 1.5 seconds — the same time it typically takes a trained officer to draw and fire a handgun.
🔹 How the Drill Works
1. Setup:
One person acts as the "attacker" with a training knife.
The other is the "defender" with a holstered training gun.
The attacker stands 21 feet away.
2. Drill:
On a signal, the attacker charges the defender.
The defender must recognize the threat, draw their weapon, and simulate firing before being reached.
3. Goal:
Demonstrate how quickly someone with a knife can close the gap.
Train for situational awareness, distance management, and decision-making under pressure.
🔹 Lessons Learned
21 feet is not a magic number — it varies by many factors:
Reaction time
Skill level
Terrain
Weapon accessibility
It’s a training tool, not a legal defense or rule.
🔹 Legal & Tactical Impact
Often referenced in use-of-force incidents.
Misuse of the Tueller Drill in legal arguments has led to controversy; some critics say it’s used to justify shootings prematurely.
Modern training emphasizes de-escalation, verbal commands, and the continuum of force alongside drills like Tueller's.