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New Developments in Understanding the Behavioral Science

Factors in the “Stop Shooting” Response



Again, it is very important to remember that the brain of the officer who is focused on his or her front sight actually works to suppress the information about whatever else is going on in front of him or her for a very brief period while the officer is engaged in focusing and shooting (Vickers, 2007, p. 54). This also holds true for the brain of the officer who is focused on kinesthetic alignment, making a decision while being distracted with intrusive thoughts or anything else that draws his or her attention away from the threat. Logically, this makes sense because it is hard to simultaneously focus equally on two things at the same time or to even think of two things at the same time especially under threats to one’s life. Neurologists such as Dr. Joseph LeDoux (1996) remind us about how and why we become very rigid, concrete, and inflexible in our attention and problem solving under this high level of stress. The more sudden and unprepared we are for the assault, the more instinctive our responses will be.


The officer reading this is likely aware of the current research and press announcements that relate to the difficulty of both talking on a cell phone and driving. The research informs us that focusing on a conversation impairs the ability to deal with visual problems while driving, such as the detection of a road hazard or the change of a driving condition, and then the processing or decisionmaking related to coping with that change (Green, 2000, pp. 212-213).


To escalate this illustration from talking on a cell phone and driving to a point where it is closer to the intensely focused experiences of an officer in a lethal force encounter, the reader should compare the ability to deal with a driving problem immediately after spilling very hot coffee on his or her lap. The reader’s immediate focus, for even a very short duration, to the problem of the pain, wetness, mess, etc., of the spilt coffee would significantly impair his or her ability to see developing problems down the road, engage in a conversation with someone else in the vehicle, be able to report what song or news item was on the radio, or even to be aware of the red light he or she just drove through.


Dr. Steve Yantis from Johns Hopkins, in his research published in The Journal of Neuroscience, helps us understand what is happening to a human being in these kinds of split attention encounters (Shomstein & Yantis, 2004).


Dr. Yantis put his research subjects in a functional MRI machine so he could observe the activity of his subjects’ brains as he challenged them with different tasks related to attention. While they were in the MRI, they were able to look at a computer screen and had headphones on so they could focus on either their hearing, their vision, or both and be able to shift back and forth between them (Shomstein & Yantis, 2004, p. 10703).


Yantis observed that when he required his subjects to focus on the computer screen with their eyes, the part of their brain associated with hearing was “turned down.” When he required the subjects to focus on their hearing through the headphones, the part of their brain dealing with vision was significantly “turned down” (Shomstein & Yantis, 2004, p. 10704). Yantis says this is because the human brain has problems dealing with more than one major item at a time. Yes, we can multitask as long as nothing we are dealing with becomes very important, in which case the brain shifts all its attention to what is important at that time and we lose the ability to detect, remember, and process other issues or items.


Officers in the street have observed that when they are focused on making their firearms work to shoot to save their lives that they too might not be able to even hear someone next to them screaming in their ear or even know that they fired their own guns or how often they fired them (Artwohl, 2002, p. 18).


Simply put, the work of Dr. Yantis illustrates and explains the attention and brain functions underlying tunnel vision and tunnel hearing. It also states that if we are focused on one thing—looking at something—and then a threat or challenge comes in through another sense, such as hearing, our response to that is going to be much slower than it normally would be.


So, if we are focused on seeing and specifically seeing what is important to us, we likely will not hear something that could be very important. Even if we did hear it, our reaction would be slower than it normally would be if we were listening for it.


Implications: So What Does All This Mean?


The implications of all of this are profound and wide ranging.


From the point of view of a trainer, it means that an officer dealing with a threat is going to react slower to that threat if they are not anticipating it or prepared for it. Also, dealing with multiple subjects in a high stress encounter is going to present an extreme challenge to the officer and trainer. Not only will the officer be able to primarily see only what he or she is focused on, but the officer’s own brain may sabotage or delay the officer’s ability to perceive and react to threats from others or even from the subject he or she is directing his or her attention to if he or she is not focused on or anticipating that specific threat. For instance, an officer focused on the subject’s right hand and expecting that hand to contain a weapon is going to react much slower if the subject has the weapon instead in his or her left hand than if he or she had anticipated from the beginning that the weapon would appear in the left hand. The officer could also speed up his or her reaction time to a weapon in the left hand if he or she were open to the option that the weapon could appear in either or both hands. In previous news lines, FSRC has discussed visual scan patterns and the influence of scan patterns on the detection of threat and the memory of that threat (Lewinski, 2008a).

The trainer needs to develop programs that will assist an officer in rapidly scanning and precisely identifying the appropriate threat components of a scenario. This may be as valuable for the officer as weapon skills. Yantis’s work and the other research we have cited in this article inform us that weapon skills are far less productive if they are not combined with great target recognition and identification skills. Further, in regards to weapon management skills, instructors must provide training for their officers that involves dynamic movement relevant to incidents they will face and also that involves tracking and shooting at subjects who also are engaged in dynamic movement.


From the point of view of an investigator and prosecutor, the implications are even more profound. The work previously cited and the illustrations of the work at Dr. Dan Simons’ visual cognition laboratory at the University of Illinois–Urbana- Champaign inform us that even under normal non-stress conditions we are seriously deluding ourselves if we think we can see, pay attention to, react to, and remember everything that we might ideally be able to see, even if it is present or happening directly in front of us (Simons & Levin, 1998). Yantis’s work tells us that even in non-stress situations, if we are focused on the information coming into one sense, such as the eye, we are less aware or even unaware of information coming into the other senses, such as taste, smell, hearing, touch, or movement (Shomstein & Yantis, 2004). From the work of both Simons and Yantis, it is clear that at least during a brief period of “focused attention,” we are “tuned down” to information coming in from another sense other than the one we are using to focus and even in that sense we are still “tuned down” to any other information coming into that very same sense—other than that information on which we are specifically focused.


Of course, in the laboratory, it is impossible to generate life-threatening situations with which the research subject needs to cope. However, street research informs us that an officer can be so focused on the threat or his or her attempt to cope with the threat that the officer literally cannot hear his or her partner screaming in his or her ear, do not notice where he or she is standing or moving to, do not record the number of rounds he or she has fired, etc. The officer also suffers significantly from an inability to perceive information that could be, at that time, tactically important to his or her own survival, let alone information that at some later point becomes significant in a court of law, based on someone else’s perception of what should have been important to the officer at the time (Artwohl, 2002, p. 18).


In the past, these errors in attending to and recording information were termed and still are referred to as perceptual distortions as if in some non-stress environment we are able to sense, process, and remember in some nondistorted way everything that occurs to us. The reality is that most of us are very poor, in fact incapable, of perceiving and recording everything that occurs to us at any particular moment. We are often so preoccupied with our own thoughts or actions and so inattentive to the world outside ourselves that we frequently are not any more aware in the present moment in non-stress situations than when in high stress life-threatening situations. Therefore, the term perceptual distortions is a misnomer. Not perceiving the totality of an event is how we normally operate. In fact, even in non-stress situations, once we focus on anything, even if it is an idea in our own head, we significantly compromise our ability to perceive, react to, and remember anything that is occurring around and to us. Has the reader ever driven to work actively engaged in some internal problem or focused on an interesting discussion only to find that they have already reached his or her destination, oblivious of being on the journey? This phenomenon, although qualitatively different than the officer who is in a high stress, life-threatening encounter, is functionally identical. An illustration the reader might relate to is one that the primary author has experienced while working on this article on a trip from England on Iceland Air. The author was listening to music and at times did not even notice the songs that had just been played or even remember that the music was on. According to Yantis, my brain had “tuned down” the background music from my ears so I could focus on what was important to me at that time, which was looking at my computer and thinking about this article. The author notes that some songs caught his attention, but then they distracted him from the attention this article required (Shomstein &Yantis, 2004).


This process of perceptual distortion has been called tunnel hearing or tunnel vision in the law enforcement world, but long before those terms entered the cop world they were being researched as a process of normal, everyday functioning under the names of selective attention, attentional focus, etc. An area of psychology entitled Attention was developed primarily to research these phenomena, and three journals dedicated to this area went into publication in the 1950s. For more information, see Niedenthal and Kitayama (1994).

What is most puzzling about all of this for the uninformed is why an officer who is in a life-threatening situation cannot remember something that is directly connected to his or her survival such as how he or she moved or shot, how many rounds were fired, or the movement of the very person he or she was shooting at to stop that person from killing him or her.


Besides the principles we have just covered, we need to refer to Tom Aveni’s research cited in a previous news line (Lewinski, 2008a). Aveni’s (n.d.) work informs us that the average officer-involved shootings, particularly those in which officers die, involve a shooting that occurs five to six feet or less from the officer. The average officer fires three rounds in response to the threat. FSRC’s research informs us that the threat can rapidly unfold—perhaps as quickly as in a quarter of a second or less (Lewinski, 2000). In this very brief, usually dynamic, visually complex, rapidly unfolding, and life-threatening encounter, the officer, for the most part, is incapable of focusing on more than one thing at a time. If, for instance, the officer is focused on drawing his or her weapon, then he or she literally cannot see what the subject is doing. If the officer is skilled and trained enough so that drawing his or her weapon is automatic and instinctive, then the officer’s mind is free to think of other things. The average officer, well-trained by current standards, can only directly focus on one other thing such as what the subject is doing, but he or she might not be able to report on where, geographically, the subject is doing this. Simons’ (2000) work tells us that if you are focused on one thing in a visual field, you cannot see another thing in that visual field without shifting your focus, so an officer who is focused on the subject’s hand on his or her waistband will not be able to see the subject’s face (without directing his or her attention to it) let alone whether or not the subject is standing next to a tree, rock, car, etc. The officer often—unless it was noted at some other time than the immediate shooting encounter—is not able to tell us where he or she is in the scene other than some vague generalizations. The investigator needs to understand that in this brief encounter, the officer is only able to be relatively accurate about what he or she is focused on, not what the investigator later thinks is important. For instance, if the officer is focused on his or her gun and the number of shots fired, the officer can be very accurate about that behavior, but in the case in which the focus is on the officer him- or herself and the rounds fired, the officer will be reasonably inaccurate about the subject’s behavior. If the officer is focused on the subject’s behavior, he or she often, for instance, cannot tell the investigator where he or she stood or accurately report his or her own behavior for that brief microsecond of time.


As stated previously, this inability to notice and react to anything other than that on which an officer is focused is not a myth generated by law enforcement officers. It is a well-documented phenomenon in cop shootings—from the early work by Dr. Roger Solomon to the current work of Drs. Artwohl, Honnig, and others (Artwohl, 1997, 2002, 2003; Honig & Roland, 1998; Klinger, 2002; Solomon, 1997; Solomon & Horn, 1986). This phenomenon has also been well-documented and explained by research in perception, attention, and cognition for over half a century. Please note the excellent summary of the literature (thousands of citations) in Niedenthal and Kitayama’s (1994) The Heart’s Eye, which focuses on almost fifty years of research on the effect of emotions on attention. Unfortunately, for a variety of reasons, the neuropsychology of why these phenomena occur has generally not reached the law enforcement world, and the law enforcement world has not reached into academia.


The general conclusion from all of this is that an officer must first perceptually and attentionally recognize that the subject has ceased to be a threat before the officer can then begin to alter his or her response to the threat. This process takes time and can result in many rounds being fired at the threatening subject for some period of time after the subject has ceased to be a recognizable threat.


Investigators in particular need to be informed about the dynamic action of subjects in deadly force encounters (Lewinski, 2000) and should use that information to help them understand shot placement or patterns of shot placement in the subject at which the officer is firing. For instance, a vehicle travelling at 10 miles per hour is going to travel about 14 and a half feet in one second. An officer standing in front of the vehicle with his or her weapon out as it begins to accelerate may take as little as 0.6 of a second to raise his or her weapon and fire one round (Lewinski, 2002) and spin to evade the vehicle. Even with this amazingly fast reaction time, which would occur without thought, the vehicle travelling at 10 miles per hour would cover over seven feet before it was hit with the first round. If the officer had any thought at all before he or she reacted, the first round to hit the vehicle would strike it after it had travelled over 14 feet. The same comparison could be made about the impact on the officer’s stop shooting response and the influence of the time to assess that the vehicle had gone by and was no longer a threat.


The chart included in Table I (Lewinski, 2009) allows investigators to also compare the officers starting and stopping time with the travel time of a human being. The darkened squares in the chart (going from right to left) allow the reader to follow the average stride time and distance for the average person, starting with the first stride (the furthest right block) and ending with the person in a full stride at a “good” pace (the farthest left block). For instance, if the reader looks at the chart, he or she can see that the average person in moderately good running shape can, for at least a short period of time, cover at least five and half feet for every stride taken and can take each stride in one quarter of a second. Considering that the average person has no problem running 10 miles per hour for a short distance, the reader can then see that the same comparison can be made with a human as with the automobile. If an officer, reacting to a threat posed by a person running at 10 miles an hour, simply, without thought or aiming, raises his or her weapon and fires, the average person will be hit with the first bullet at a distance of seven or more feet away from where he or she first presented the threat, and that person will likely be in a different physical position.






Table 1. Speed of Person in Miles per Hour by Stride Length and Speed per Stride in Seconds


On average, it was found that when youthful, vigorous, relatively fit people start to run, their first step takes about .35 of a second (not counting reaction time) and covers 1.5-2.0 feet. Their second step requires about .34 of a second and covers about 3.0 feet. Their third takes about .33 of a second and the stride lengthens to 3.5 to 4.0 feet... and so on. Typically, after 5 to 7 steps, people max out at about .25 of a second per 5.5- to 6.0-foot stride, which they can then maintain for a short period of time.

It is the responsibility of investigators to inform themselves of these phenomena and their implications for officer performance and memory in a lethal force encounter.





The following conclusions can be drawn from the theoretical research, applied research, clinical research, and the experiences of law enforcement officers who have survived lethal force encounters:


• An officer is usually not able to immediately see and react to changes in the subject(s) at whom he or she is shooting. This is not determined by whether that change is an increase or a decrease in the threat presented to the officer by the subject.


• The focus of the officer’s attention—internal or external, specific or general, near or far, and left or right—will determine the officer’s “ability” to perceive and react to changes in the threat and also the length of time it takes for the officer to perceive and then react to that change.


• The delay in noticing any change in the nature of the threat and having the officer change his or her behavior in response to that threat could theoretically take the average officer a second to a second and a half in a dynamic, “real- world,” life-threatening encounter if the officer did not expect that the threat would cease. This process alone could be the reason for an extra three to six rounds being fired by the officer after the threat ceased—particularly if the officer was shooting as quickly as possible, was focused on shooting to save his or her own life, or emotionally recoiling in response to that threat and also simultaneously involved in assessing the threat. Of course, the more an officer is directly focused on the threat, the quicker a change can be identified and the officer can stop shooting.


• Officers will both start and stops hooting based on a variety of factors, including their visual angle on the incident and their ability to perceive the threat, their attentional and reactive capabilities, their weapon skills, and their psychomotor movement times.


It is one of the stated missions of FSRC to bring to law enforcement the current scientific research at FSRC and other universities. This article is written to further that end.




For their assistance in the development of this article, special thanks need to be given to Dr. Jonathon Page, a cognitive psychologist with the Psychology Department at Minnesota State University, Mankato and an FSRC technical advisory board member; Dr. Kent Kalm, professor in the Human Performance Department at Minnesota State University, Mankato and an FSRC technical advisory board member; and Sgt. Craig Stapp, Lead Firearms Instructor with the Tempe, Arizona, Police Department and an FSRC technical advisory board member.





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William J. Lewinski is a behavioral scientist specializing in law enforcement- related issues. He has a Ph.D. in Psychology with a concentration in police psychology and is a tenured, full professor in the Law Enforcement Program at Minnesota State University, Mankato. He is the founder and director of the Force Science Research Center at Minnesota State University, Mankato, and the CEO of the Force Science Institute, Ltd. Dr. Lewinski is conducting the leading research on human behavior in force encounters. He has over 30 years of experience studying officer-involved shootings.


Christa Redmann is currently a senior Psychology major at Bethany Lutheran College in Mankato, Minnesota. She is minoring in both Business and Sociology. She has been a research intern and is currently a research assistant with the Force Science Institute.