A Traffic Stop Experiment

There is no way to predict and few ways to categorize the actions that occur during a traffic stop.


LET predicted that response to threats would be significantly improved if the officer knew what he was facing prior to the stop. If correct, officers faced with a known threat would deploy the correct tool and engage quicker than officers facing an unknown threat. Not only did data suggest this was true, the times were significantly faster and the hits were significantly more accurate.

During the last iterations, LET experimented with "known threat" scenarios, meaning officers were told the suspect had a firearm prior to the start of the scenario. Furthermore, the suspects were told to exit the vehicle firing. During an iteration, an officer delivered a "fatal" shot to the suspect within 0.34 seconds. In another, the same officer hit a vital area within 0.2 seconds.

First tool deployed is fastest

There is a time lag between the decision and action of an officer on a traffic stop. This time lag needs to be factored in between when an officer deploys his force option and the scenario changes. On several scenarios, the suspect quickly exited the vehicle appearing unarmed. After a couple of steps, ignoring the officer's verbal commands, the suspect drew a weapon from his clothing. During the time between a suspect's status change from "unarmed" to "armed," the suspect could cover as much as 10 feet. Sometimes the suspect was not aware that he was closing the distance on the officer.

This time lag issue is alarming. First, if the suspect moves toward the officer before drawing a weapon, the 30 feet that the officer originally had as a "cushion" has diminished by a third. Second, when a suspect randomly rushes an officer from the full distance of the traffic stop, he makes physical contact in a couple of seconds. Twice a suspect exited the vehicle and made physical contact with an officer within 1.5 seconds, once within 1.16 seconds.

This issue with time lag was the most sobering whenever a suspect exited the vehicle and rushed the officer. The officer responded to a charging suspect by drawing his weapon. By the time it appeared that the suspect was unarmed, the officer was in danger of being disarmed. Though the officer fired his weapon, scoring combat effective hits, LET recognized the danger of the officer being disarmed by the suspect. Bear in mind no one except the suspect knew what the suspect was going to do. It appeared that even if the officer exited his doorway and moved diagonally away from the suspect's direction, the distance cushion was far too diminished.

What should the officer have done to prevent firing on an unarmed suspect? Should he have moved diagonally or tangentially from the suspect's direction of travel? If the officer had, and the suspect was armed, the officer just broke from cover. If the suspect was armed with an edged weapon, the patrol car door would have been reasonable cover. Additionally, an edged weapon-wielding assailant would have been a reasonable deadly force option. If the officer decided that deadly force was not the correct force option after presenting a firearm, he would have had to make a decision within the last 10 feet of the suspect's travel. Interestingly enough, data established 10 feet was not enough cushion for OC deployment in several iterations.

Practice improves response

If LET's theory was correct, two trends would occur. Response times to threats would steadily decline, and the percentage of appropriate and effective response would increase as data collection continued. Additionally, if response times improved, accuracy would improve. As it would be unlikely officers would shoot a consistent number of rounds for each scenario, a hit/miss ratio measured accuracy, rather than the number of hits.

LET's prediction was consistently true. At the beginning of the experiment, officers fired more rounds with fewer hits. Initially, officers averaged a 1:3 hit/miss ratio. At the end of the experiment, the average rose to a 5:6 hit/miss ratio. Further, the time it took for officers to respond decreased from 1.09 to 0.66 seconds as the experiment continued, despite which officer rotated into the scenario.

Early OC deployment is best

It is hard to hit a moving target with OC. Purchasing inert OC training canisters is an excellent investment. In some scenarios, the suspect was nearly at a contact distance by the time an effective dose of OC was delivered. Also found was an improvement in OC deployment as time went on.

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