06/09/2026
21 feet won't save you. Most people who quote the "21-foot rule" have never read the original research, and the cop who wrote it never called it a rule.
The scenario it describes is one most of us have imagined: someone with a knife is closing the distance. Your firearm is holstered. Can you draw and fire before they reach you? For 40 years, the answer most trainers gave was yes, at 21 feet. The research now says that's wrong.
In 1983, Sgt. Dennis Tueller of the Salt Lake City PD published "How Close Is Too Close?" in SWAT magazine. He timed volunteers sprinting at a target--21 feet in 1.5 seconds. That was about the same time it took an officer to draw and fire. Tueller called it a danger zone. He told officers to use cover and create obstacles. He never called it a rule.
In 2020, a peer-reviewed study at Texas State University / ALERRT (152 officers, published in Police Practice and Research) measured real-world draw times. The average came in at 1.80 seconds, slower than the 21-foot sprint. The researchers concluded that for 95% of officers to fire on target before an edged-weapon attacker reaches them, the distance needs to be
closer to 30 feet.
Force Science Institute has separately documented sprint-and-slash attacks completed from 30 feet in 1.67 seconds.
The fix isn't a new number to memorize. It's what Tueller actually wrote: recognize pre-attack indicators early, create distance, use cover. Action beats reaction every time--anticipation is what gets you out of the gap.
Save this. Share it with anyone who carries, and anyone who's been told they can outdraw a knife at "the magic distance."
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*Sources: Tueller, "How Close Is Too Close?" SWAT Magazine (1983). Sandel et al., Police Practice and Research, Texas State / ALERRT (2020). Force
Science Institute publications (2005–2022). The Tueller drill is a training principle, not a legal standard — use-of-force decisions are evaluated under the totality of the circumstances.*