Tueller Drill

The Tueller Drill is a situational awareness and reaction-time exercise designed to illustrate the danger posed by an attacker armed with a melee weapon at close range, that underscores how quickly a close-range threat can escalate. Tueller did his tests and studies at 21 feet (6.4 metres, 7 yards) because it was already common for officers to train to shoot from this distance. Tueller found that a person would be in danger if an attacker came at him from this distance.^[1] According to NRA publication Shooting Illustrated, the Tueller Drill evolved into a "21-foot rule," which is the idea that an attacker can close a distance of 21 feet within 1.5 seconds, and that therefore 1.5 seconds is generally taken to be the minimum response time facing a threat.^[2][3]

Sergeant Dennis Tueller of the Salt Lake City Police Department wondered how quickly an attacker with a knife, or other melee weapon, could cover 21 feet (6.4 m), so he timed volunteers as they raced to stab the target. He determined that it could be done in 1.5 seconds. These results were first published as an article in SWAT magazine in 1983 and in a police training video by the same title, "How Close Is Too Close?"^[4][5]

The "21-foot rule" has been implemented in some police department policies, and was the focus of a dissent in the excessive force case Buchanan v. City of San Jose where police officers shot a knife wielding person at a distance of 55 feet.^[6]

MythBusters covered the drill in the 2012 episode "Duel Dilemmas". At 20 ft (6.1 m), the gun-wielder was able to shoot the charging knife attacker just as he reached the shooter. At shorter distances the knife wielder was always able to stab prior to being shot.^[7]

A defender with a weapon has a dilemma. If he shoots too early, he risks being accused of murder. If he waits until the attacker is definitely within striking range so there is no question about motives, he risks injury and even death. The Tueller experiments quantified a "danger zone" where an attacker presented a clear threat.^[8]

The Tueller Drill combines both parts of the original time trials by Tueller. There are several ways it can be conducted:^[9]

1. يتمركز المهاجم (المُحاكى) والرامي ظهراً لظهر. عند الإشارة، ينطلق "المهاجم" مبتعداً عن الرامي، فيسحب الرامي مسدسه ويطلق النار على الهدف الذي يبعد عنه 6.4 متر (21 قدماً) . يتوقف المهاجم فور إطلاق النار. يُعتبر الرامي ناجحاً فقط إذا كانت إصابته دقيقة ولم يقطع العداء مسافة 6.4 متر (21 قدماً ) .  
2. يتمثل الترتيب الأكثر إرهاقًا في أن يبدأ المهاجم من مسافة 6.4 متر (21 قدمًا ) خلف مطلق النار ويركض نحوه. ولا ينجح مطلق النار إلا إذا تمكن من توجيه ضربة دقيقة قبل أن يربت المهاجم على ظهره. 
3. إذا كان المُطلق مُسلحًا بمسدس تدريبي فقط، فيمكن إجراء تدريب على مواجهة كاملة مع المهاجم وهو يركض نحوه. في هذا التدريب، ينبغي على المُطلق التدرب على تفادي المهاجم جانبًا أثناء سحبه للمسدس.

• ساندل، ويليام ل.؛ مارتينديل، م. هنتر؛ بلير، ج. بيت (26 مارس 2021). "دراسة علمية لقاعدة الـ 21 قدمًا". ممارسات الشرطة وبحوثها . 22 (3): 1314-1329 . doi : 10.1080/15614263.2020.1772785 . S2CID 219765729 .