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Force Science validates legacy research findings

Whether aimed or not, it is clear that firearm assaults can be much faster than the time needed for an effective response

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Originally published on the Force Science Institute website. Republished here with permission.

By Lewis “Von” Kliem, MCJ, JD, LLM, and David Blake, Ph.D.

In 2000, Force Science published “Why is the Subject Shot in the Back?” a research summary detailing the speed at which people can shoot, turn and move from various positions. [1] For over 20 years, this Force Science research informed our understanding of deadly force encounters and that of police, communities, and courts worldwide.

Advances in speed and movement measurements inspired Dr. Bill Lewinski, Senior Researcher and Executive Director at Force Science to re-evaluate the speed of firearm assaults. Joining researchers from Rocky Mountain University, Utah, Force Science used high-tech body sensor technology and video to continue their investigation into stationary and dynamic shooting movements.

Studying body motions

Force Science, along with lead researcher Michael Kantor and colleagues within the Department of Research and Sponsored Projects, analyzed the body motions associated with eight common shooting encounters.

This “kinematic” study included movements explored in earlier Force Science studies, including how fast a person can:

  1. Shoot from a vehicle
  2. Draw from their waistband and fire a handgun while standing
  3. Fire, turn and run from an officer.

The results of this peer-reviewed study, titled Kinematic Analysis of Naive Shooters in Common Law Enforcement Encounters, were recently published in the Journal of Forensic Biomechanics (2022). [2]

In this next series of articles, we will detail the results of this latest study, beginning with how fast people can shoot from vehicles. We will compare the recent Rocky Mountain study to earlier Force Science research and explain how these findings advance our understanding of dynamic force encounters.

Time to Shoot: Seated in Vehicle

Early Force Science research (2000) found that participants sitting in either the driver or passenger side of a simulated vehicle could move a handgun concealed beside their thigh (at the center console), point, and rapidly shoot (unaimed) out of the nearest window in an average of about one-quarter of a second (.25s). [3] The fastest times were closer to one-tenth of a second (.10s). For comparison, the blink of an eye can take close to one-third of a second (.30s).

In a 2013 peer-reviewed study, The Influence of Officer Positioning on Movement During a Traffic Stop Scenario, Force Science researchers added additional realism to the shooting scenarios. Seated in a vehicle, using a handgun equipped with training rounds (Simunition), the driver was able to aim, track the officers, and fire out of either the driver-side or passenger-side front window in an average of around half a second (.50s). The fastest aimed shots in the study were just over one-third of a second (.30s).

In the latest 2022 Rocky Mountain study, researchers used video and motion sensor technology (accelerometers and gyroscopes) to once again investigate a “driver’s” shooting movements and speed.


Figure 1: Shooting from the driver-side front from 2000 and 2022.

With the high-tech measuring devices, researchers were able to validate legacy Force Science research findings. Specifically, in the Rocky Mountain study, the average time a driver could move, aim, and fire out the driver’s side window was half a second (.50s). The fastest time was about a quarter of a second (.26s).

When drivers fired out of the passenger side window, the average time to move, aim, and fire was just over half a second (.64s), with the fastest time being closer to a third of a second (.35s).


Figure 2: Shooting from the driver-side front from 2013 and 2022.

When the 2022 Rocky Mountain findings are compared to the results of the 2013 Force Science “traffic stop” study, shooting times involving aimed fire from a vehicle were nearly identical.


Table 1: Time to shoot study comparison.

Aimed or Unaimed: Deadly Fast

Although the above research confirms that aimed fire is slower, it is still dangerously fast. And, although aimed fire can take twice as long as unaimed fire, readers are cautioned not to dismiss the faster shooting times observed in the 2000 study. Video evidence of real-world shootings continues to validate that offenders often do not take time to aim, and that firearm assaults can still be executed in close to one-tenth of a second (.10s).

Whether aimed or not, it is clear that firearm assaults can be much faster than the time needed for an effective response. Research has shown that the average officer expecting an assault may respond in an average of 1.8s to draw from the holster and return defensive fire. [4]

Even where officers have already drawn and presented their firearms in a “high-ready” position (pistol held extended just below the officer’s line of sight), laboratory research has shown an average response time to return fire of .83 seconds. [5]

It is important to note that participants in laboratory experiments of this type are focused on a clear “go” signal and have already decided their response will be to fire their handgun. Generally, these two factors are not present in real-world encounters, meaning that threat recognition and decision-making time must be included when evaluating the officer’s total response time.

Laboratory research should be considered a baseline – demonstrating the fastest an officer can react in similar lab conditions – with an understanding that real-world response times can be much longer. In the Force Science “traffic stop” study, officers faced an unknown threat across three trials – of which only one was intended to end in a deadly force encounter. The officers were required to perceive the threat and then make and execute their decisions. This resulted in some officers taking nearly 2.5s to move, draw, and respond with aimed fire. [6] Supporting these findings, we have reviewed real-world deadly force encounters in which involved officers’ response times were over three seconds.

Don’t Just Stand There. Do Something

In a January 2020 article, You Don’t Have to Shoot First; But You Better Do Something, Force Science reminded readers of the immense difficulty of identifying and responding to real-world assaults. In light of the latest research validating the dangerous speed of assaults, there are warnings worth repeating here:

[Do] officers have to shoot first? No; but they better do something.

Move. Create distance. Find cover. De-Escalate. All great ideas under the right circumstances.

Of course, under the right circumstances, initiative, surprise, and speed may be better options. [7]

Sometimes officers can safely disengage, reconsider their approach, and avoid the fight altogether. Often, they can’t.

To avoid split-second decisions, [officers] have learned to recognize and value threat cues and suspicious patterns of conduct (schemas). Knowing the speed of assaults is why they give orders and prioritize tactics that reduce a suspect’s ability, opportunity, and willingness to assault them.

When circumstances tend toward a possible armed assault, speed studies remind officers to aggressively look to buy time, create space, and negotiate from positions of advantage; before the threat materializes…and so that nobody has to shoot first.

Nearly twenty-five years ago, Dr. Lewinski similarly cautioned:

If there is one primary lesson for the officer to take from this study, it is the value of good basic officer survival skills, such as pre-event decision-making, visual and mental alertness, tactical positioning, and always having the suspects keep their hands in view.”

Today, Rocky Mountain researchers and Dr. Lewinski reinforce these vital observations, “[T]hese findings suggest that if a law enforcement officer does not or cannot take pre-emptive measures to avoid or control the situation, they simply lack sufficient time to react and respond to the stimulus, prior to taking fire…” “Therefore, we reiterate the need to incorporate these studies in police tactical training so officers may be better informed and subsequently make decisions that have increased potential to mitigate dangerous situations.”


Previous Force Science research measured the speed of drawing and firing from the waistband and how fast people can shoot and move. This early research has been vital to understanding bullet impact locations and has been some of the most influential research in understanding deadly force encounters.

In the next Force Science News, we will continue to report on the Rocky Mountain study and share the critical details that emerged in our understanding of movements and speeds associated with deadly firearm assaults.


1. Lewinski B. (2000). Why is the suspect shot in the back? The Police Marksman, 25(6):20-28.

2. Kantor M, Lewinski W, Garg H, Tenbrink J, Lau J, Pettitt R. (2022). Kinematic Analysis of Naive Shooters in Common Law Enforcement Encounters. Journal of Forensic Biomechanics, 13:405.

3. See note 1.

4. Sandel WL, Martaindale H, Blair JP. (2020). A scientific examination of the 21-foot rule, Police Practice and Research.

5. Bushey J, Dicks N, Dysterheft J, Lewinski W. (2015). Ambushes Leading Cause of Officer Fatalities – When Every Second Counts: Analysis of Officer Movement from Trained Ready Tactical Positions. Law Enforcement Executive Forum, 15

6. Lewinski, et al. (2012). The influence of officer positioning on movement during a threatening traffic stop scenario. Law Enforcement Executive Forum.

7. See Dysterheft J, Lewinski W, Pettitt R, O’Neill D. (2013). The influence of officer positioning on movement during a threatening traffic stop scenario. Law Enforcement Executive Forum, 13: 98-109. Multiple research subjects prevented the “armed attack” by quickly moving toward the suspect and controlling or deflecting the weapon.

About the authors

Lewis “Von” Kliem, MCJ, JD, LLM, has worked as a civilian police officer, attorney, educator and author. Von is the executive editor of Force Science News and co-owner of Von Kliem Consulting, LLC, where he trains and consults on constitutional policing, use of force analysis, crisis communications and trauma-informed interviewing.

David Blake, Ph.D., is a retired California peace officer and a court-certified expert on human factors psychology and the use of force. He has significant experience teaching use of force and human factors psychology to law enforcement officers in several states. David has undergraduate and graduate degrees in criminal justice and psychology. He has authored over 30 professional and peer-reviewed journal articles on the application of human factors psychology to first responders and their operational environments. David continues to conduct research on police deadly force and human factors psychology. He is the lead consultant at Blake Consulting and Training.

The FSRC was launched in 2004 by Executive Director Bill Lewinski, PhD. -- a specialist in police psychology -- to conduct unique lethal-force experiments. The non-profit FSRC, based at Minnesota State University-Mankato, uses sophisticated time-and-motion measurements to document-for the first time-critical hidden truths about the physical and mental dynamics of life-threatening events, particularly officer-involved shootings. Its startling findings profoundly impact on officer training and safety and on the public’s naive perceptions.
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