The Tueller Radius
In 1983, an article written by a Salt Lake City police officer named Dennis Tueller was published in a law enforcement journal. The article was titled “How Close is too Close?” and it dealt with the premise of a man armed with a holstered handgun defending against a man armed with a striking or stabbing instrument. Through experimentation, Tueller concluded if a bad guy armed with a knife or a club was within 21 feet of you, the reasonable conclusion would be you were within his danger zone. In other words, the bad guy could cover 21 feet in about 1.5 seconds—before you could draw your handgun and neutralize the threat.
And, what we have seen is an ongoing 32-year debate about how fast a human being can move...
Tueller's point, and the point of this article by Richard Mann, is awareness.
/fl