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Force Science Reactionary Gap

NCJ Number
Chris Wisecarver; Melvin Tucker
Date Published
September 2007
3 pages
This article reviews findings from research conducted on human performance in lethal force encounters, specifically the action/reaction parameters, also known as the reactionary gap, offering training recommendations to ensure officer safety and a clear understanding of probable cause and the U.S. Constitution.
In high-risk encounters it was found that (1) a suspect could draw a firearm from his waistband and fire from the hip in an average time of .23 seconds, (2) a suspect could draw a firearm from his waistband, extend his arms and fire in an average time of .26 seconds, and (3) an officer with his firearm securely holstered required an average of 1.71 seconds to draw the firearm, get on target, and fire. Officers should be taught that the best way to survive a high-risk encounter is to move backwards or laterally toward cover to get the benefit of reactionary gap. During a vehicle stop, a suspect with a firearm beside him while in the driver’s seat can draw and bring the firearm across his body and over his shoulder, point to the rear and fire in an average of .25 seconds. If the officer needs to approach a stopped vehicle, it is recommended they conduct a tactical passenger-side approach. When the officer directs the driver out of the car, it is recommended that the officer use his open door as available cover. In foot pursuits, when a suspect is running away from an officer with a firearm, the officer should attempt to maintain visual contact until back-up arrives. Research by Dr. Bill Lewinski, shows that officers have little time to make decisions about the use of force. This research into human performance in lethal force encounters observed and timed suspect and officer movements with a concentration on the action/reaction parameters, referred to as the “reactionary gap” in the areas of high risk encounters, vehicle stops, and foot pursuits. The concept, that it always takes longer to react than act, has been used in officer safety training.