Research

Protective Vests in Law Enforcement: A Pilot Survey of Public Perceptions (2017)

O’Neill, J., Swenson, S. A., Stark, E., O’Neill, D. A., & Lewinski, W. J.

 

Publication: Journal of Police and Criminal Psychology

The primary purpose of this study was to begin an examination of the relationship between public perception and the number of attachments on external protective vests worn by law enforcement. A secondary purpose was to examine perceptual differences between non-law enforcement majors and law enforcement majors. Images of six vests that systematically varied in the amount of external attachments were rated across eight attributes: (1) approachability, (2) militarized appearance, (3) intimidation, (4) professional appearance, (5) organization, (6) confidence instilled in an officer, (7) confidence instilled in the public, and (8) recognizable as law enforcement. Vests with more external attachments were rated as more militarized and intimidating. However, participants also rated militarized appearance and intimidation as the least important attributes when considering external protective vests. Confidence instilled (by the images of vests) in an officer, and in the public, were the highest rated attributes, respectfully. These findings suggest that a militarized and intimidating appearance might not detract from the public’s overall acceptance of external protective vests in law enforcement. In addition, law enforcement majors and non-law enforcement majors differed significantly in their ratings of all eight attributes. This suggests that exposure to law enforcement education might affect public perceptions of external protective vests. It is possible that education of the public on the function (e.g., load distribution) of external protective vest attachments might offset negative perceptions.

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Toward a Taxonomy of the Unintentional Discharge of Firearms in Law Enforcement (2017)

John O’Neill, Dawn A. O'Neill, and William J. Lewinski

 

Publication: Applied Ergonomics

An unintentional discharge (UD) is an activation of the trigger mechanism that results in an unplanned discharge that is outside of the firearm’s prescribed use. UDs can result in injury or death, yet have been understudied in scientific literature. Pre-existing (1974 to 2015) UD reports (N = 137) from seven law enforcement agencies in the United States of America were analyzed by context, officer behavior, type of firearm, and injuries. Over 50% of UDs occurred in contexts with low threat potential while engaged in routine firearm tasks. The remaining UDs occurred in contexts with elevated to high threat potential during muscle co-activation, unfamiliar firearm tasks, contact with inanimate objects, and a medical condition. An antecedent-behavior- consequence (A-B-C) taxonomy as well as a standardized reporting form, based on the current findings and the existing literature, are offered as tools for identifying the conditions under which UDs may be likely to occur.

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The Speed of a Prone Subject (2016)

Lewinski, W. J., Seefeldt, D. A., Redmann, C., Gonin, M., Sargent, S., Dysterheft, J., & Thiem, P.

 

Publication: Law Enforcement Executive Forum

A within-in subjects research design was used to examine the dangerousness of an assailant in the prone position in relation to the speed at which the individual with “hidden hands” can fire a weapon. Forty participants were recruited to fire a handgun in five directions from a prone position. Each participant’s initial area of body movement and time to weapon discharge was recorded. Results suggest that partici-pants can fire a weapon from the initial movement of any body part to discharge in a little over half a second (M = 0.61 s), and the time from first object sighting (noting something was in the hands) to discharge was approximately one-third of a second (M = 0.36 s). Repeated measures analysis indicated that the fastest shooting times occurred in the chest up position. The head and upper body most commonly moved first when participants shot from the chest up position, while participants first moved their feet and lower body in all other positions. Lack of previous research points to the novel nature of this article. The speed with which a prone subject can turn and fire a weapon can be applied to officer training and policy.

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Memory and the Operational Witness: Police Officer Recall of Firearms Encounters as a Function of Active Response Role (2016)

Lorraine Hope, David Blocksidge, Fiona Gabbert, James D. Sauer, William Lewinski, Arta Mirashi, & Emel Atuk

 

Publication:  Law and Human Behavior

Investigations following critical events often depend on accurate and detailed recall accounts from operational witnesses (e.g., law enforcement officers, military personnel, emergency responders). However, the challenging, and often stressful, nature of such events, together with the cognitive demands imposed on operational witnesses as a function of their active role, may impair subsequent recall. We compared the recall performance of operational active witnesses with that of non-operational observer witnesses for a challenging simulated scenario involving an armed perpetrator. Seventy-six police officers participated in pairs. In each pair, one officer (active witness) was armed and instructed to respond to the scenario as they would in an operational setting, while the other (observer witness) was instructed to simply observe the scenario. All officers then completed free reports and responded to closed questions. Active witnesses showed a pattern of heart rate activity consistent with an increased stress response during the event, and subsequently reported significantly fewer correct details about the critical phase of the scenario. The level of stress experienced during the scenario mediated the effect of officer role on memory performance. Across the sample, almost one-fifth of officers reported that the perpetrator had pointed a weapon at them although the weapon had remained in the waistband of the perpetrator’s trousers throughout the critical phase of the encounter. These findings highlight the need for investigator awareness of both the impact of operational involvement and stress-related effects on memory for ostensibly salient details, and reflect the importance of careful and ethical information elicitation techniques.

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The real risks during deadly police shootouts: Accuracy of the naive shooter (2015)

William Lewinski, Ron Avery, and Jennifer L. Dysterheft, Nathan D. Dicks, Robert Bushey

 

Publication: International Journal of Police Science Management

This study aimed to examine the level of shooting accuracy demonstrated by law enforcement recruits upon completion of their law enforcement firearms training in comparison with novice shooters. One hundred and ninety-five male and 52 female law enforcement recruits volunteered. Participants were separated by firearms experience into the following groups: expert (completed law enforcement firearms course, n = 83), intermediate (recreational experience, n = 71) and novice (minimal/no experience, n = 93). All subjects were tested for accuracy at target locations from 3 to 75 ft. For all locations, no difference was found in accuracy between expert and intermediate groups (p > 0.30). Experts and intermediates had better results than novices on all locations (p < 0.05) except from 3 to 15 ft. Alarmingly, experts were only 10% more accurate than novices between 3 and IS ft. Finally, novices and intermediate shooters were more likely to hit head locations from 3 ft (57%), whereas experts mainly hit the body location (78%). The results of this study indicate that officers had no advantage over intermediate shooters and a small advantage over novices.

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The Influence of Officer Equipment and Protection on Short Sprinting Performance (2015)

William Lewinski, Jennifer L. Dysterheft, Nathan D. Dicks, Robert W. Pettitt

 

Publication: Applied Ergonomics

As advances in protective equipment are made, it has been observed that the weight law enforcement officers must carry every day is greatly increasing. Many investigations have noted the health risks of these increases, yet none have looked at its effects on officer mobility. The primary purpose of this study was to examine the influence of both the weight of officer safety equipment, as well as a lateral focal point (FP), on the stride length, stride velocity, and acceleration of the first six strides of a short sprint. Twenty male law enforcement students performed two maximal effort sprint trials, in the participating college's gymnasium, from each of four starting positions: forwards (control position), backwards, 90° left, and 90° right. Subjects placed in the FP group (n = 9) were required to maintain focus on lateral FP during the 90° left and 90° right trials, and a forwards FP during the backwards trials. On a second testing date, subjects repeated the sprint tests while wearing a 9.07 kg weight belt, simulating officer equipment and protective gear. The belt averaged 11.47 ± 1.64% of subject body mass. A significant main effect of weight belt trials was found (F = 20.494, p < 0.01), in which significant decreases were found for velocity and acceleration. No other significant effects were found as a result of starting position or focal point and no significant interactions were found between independent variables. Conclusively, the results of this study show the increasing weights of duty gear and protective equipment have detrimental effects on officer velocity and acceleration, impeding their mobility, which may be dangerous in use of force or threatening situations.

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Ambushes Leading Cause of Officer Fatalities – When Every Second Counts: Analysis of Officer Movement from Trained Ready Tactical Positions (2015)

William Lewinski, Jennifer L. Dysterheft, Jacob M. Bushey, Nathan D. Dicks

 

Publication: Law Enforcement Executive Forum

Recently, the threat of ambush assaults to police of cers has dangerously increased. These assaults can occur very rapidly, and to be better prepared to respond, it is important to understand the speed of of cer responses and any advantages of cers may gain from various tactical techniques. Therefore, the purpose of this study was to understand and examine of cer movement times from various  nger-indexing positions as well as the speed at which of cers can  re their weapons from various starting positions. In the  rst experiment, of cers (n = 52)  red their weapons from four trained  nger-index positions to measure their time to  re. In the second experiment, of cers (n = 68)  red their weapons from various starting, or tacti- cally ready, positions to measure the speed of movement to weapon discharge. Results of Part One showed that contrary to training, all indexing positions were similar in time to contact the trigger, except indexing high on the slide. Part Two revealed that point shooting was signi cantly faster than aimed shooting as well as that the Low-Ready position was the fastest from which to  re, and the High-Guard ready position was the slowest. These results may provide analytical and training implications to improve the safety of of officers.

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The Influence of Officer Positioning on Movement During a Threatening Traffic Stop Scenario (2014)

William Lewinski, Jennifer L. Dysterheft, Dawn A. Seefeldt & Robert W. Pettitt

 

Publication: Law Enforcement Executive Forum

Conducting traffic stops is a routine patrol duty of police officers. The most frequent and visible interactions between police officers and the public take place in motor vehicles, most commonly at roadside traffic stops (Eith & Durose, 2011; Harris, 1989; Pinizzotto, Davis, & Miller, 2008). Officers successfully complete the majority of “routine” traffic stops without facing the threat of injury; however, traffic stops can place officers at risk of injury or death either by intended or unintended actions by an assailant or others (Payton, 1964). According to the California Commission on Peace Offi- cer Standards and Training (2005), traffic stops “can be one of the most dangerous duties a patrol officer can perform” (p. 1-3). In a study investigating officer attacks while performing routine traffic stops, one officer reported that as he approached the back door of the vehicle and informed the driver he was stopped for speeding, the driver’s only response was “two shots in the chest from a handgun . . . into my vest” (Pinizzotto et al., 2008). From 2001 to 2010, approximately 60 of 541 officers who were feloniously murdered in the line of duty were killed during a traffic stop, and 55,000 were injured during a traffic stop or pursuit (Federal Bureau of Investigation [FBI], 2010; U.S. Department of Justice, 2011).

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Police Officer Reaction Time to Start and Stop Shooting: The Influence of Decision-Making and Pattern Recognition (2014)

William Lewinski, William  B. Hudson, and Jennifer L. Dysterheft

 

Publication: Law Enforcement Executive Forum

During firearms instruction and training, law enforcement officers most often shoot one round at a time in response to an audi- tory signal, while in a controlled and rela- tively, relaxed setting (Adams, McTernan, & Remsberg, 2009). Conversely, when officers are in a critical, high stress situation with a threatening suspect, they are encouraged to shoot as many rounds as necessary, as quickly as possible, and to continue until the threat stops (Adams et al., 2009; Squires & Kennison, 2010). This type of shooting stems from pre- vious research and experience in the polic- ing field as, oftentimes, unlike common por- trayal in movies, threatening suspects are not stopped with only one round fired by officers. This is supported by medical research as it has been found that 64% of gunshot victims with wounds to the chest and abdomen and 36% of those with wounds to the head and neck can survive more than five minutes, some even able to perform strenuous activity and to continue to physically fight (Adams et al., 2009; Levy & Rao, 1988; Newgard, 1992; Spitz, Petty, & Fisher, 1961). These unexpected med- ical responses occurred in the infamous FBI Miami Shootout in which two suspects who were shot in critical locations, including the spine, lung, and head, were able to continue fighting, killing two FBI agents and wound- ing six more (Federal Bureau of Investigation [FBI], 1986) Thus, for the safety of officers and others during dangerous encounters, officers are encouraged to use a continuous and rapid shooting technique until the threat is com- pletely controlled (Adams et al., 2009).

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The Influence of Start Position, Initial Step Type, and Usage of a Focal Point on Sprinting Performance (2013)

William Lewinski, Jennifer L. Dysterheft, Dawn A. Seefeldt & Robert W. Pettitt

 

Publication: International Journal of Exercise Science

For many athletes, sprinting acceleration is vital to sport performance. The purpose of this study was to observe the influences of starting position, type of initial step taken, and a focal point on sprinting velocity, stride length, and acceleration over a 9.1 m distance. Two trials of four conditions were video recorded in which subjects had no focal point (n = 10) or a lateral focal point (n = 9). The four conditions were: forwards (control), backwards, 90° left (90°L), and 90° right (90°R). Lower velocities (p > 0.05) were observed with focal point usage from the 90°R and 90°L starting positions. Four initial steps were observed during the forwards, 90°L, and 90°R conditions: backwards step, anterior tilt with forward step, pivot-crossover step, and lateral side step. The use of a backwards step resulted in an increased velocity (+0.80 m·s-1, p < 0.01) for the 90° turn trials and increased acceleration (+ 0.37 m·s-2, p < 0.01). Our results indicate that looking at a target can cause a decline in sprint velocity and acceleration over a short distance. Moreover, utilizing a backwards step to initiate a 90° turn may generate more power and force, increasing their velocity for short sprints. We recommend training athletes with a target or focal points to help combat the reduced speed and initiate movement with initial backwards step.

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The Influence of Officer Positioning on Movement during a Threatening Traffic Stop Scenario (2013)

William Lewinski, Jennifer L. Dysterheft, Dawn A. Seefeldt & Robert W. Pettitt

 

Publication: Law Enforcement Executive Forum

Conducting traffic stops is a routine patrol duty of police officers. The most frequent and visible interactions between police officers and the public take place in motor vehicles, most commonly at roadside traffic stops (Eith & Durose, 2011; Harris, 1989; Pinizzotto, Davis, & Miller, 2008). Officers successfully complete the majority of “routine” traffic stops without facing the threat of injury; however, traffic stops can place officers at risk of injury or death either by intended or unintended actions by an assailant or others (Payton, 1964). According to the California Commission on Peace Offi- cer Standards and Training (2005), traffic stops “can be one of the most dangerous duties a patrol officer can perform” (p. 1-3). In a study investigating officer attacks while performing routine traffic stops, one officer reported that as he approached the back door of the vehicle and informed the driver he was stopped for speeding, the driver’s only response was “two shots in the chest from a handgun . . . into my vest” (Pinizzotto et al., 2008). From 2001 to 2010, approximately 60 of 541 officers who were feloniously murdered in the line of duty were killed during a traffic stop, and 55,000 were injured during a traffic stop or pursuit (Federal Bureau of Investigation [FBI], 2010; U.S. Department of Justice, 2011

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Witnesses in Action: The Effect of Physical Exertion on Recall and Recognition (2012)

 Lorraine Hope, William Lewinski, Justin Dixon, David Blocksidge & Fiona Gabbert

 

Publication: Psychological Science

Understanding memory performance under different operational conditions is critical in many occupational settings. To examine the effect of physical exertion on memory for a witnessed event, we placed two groups of law-enforcement officers in a live, occupationally relevant scenario. One group had previously completed a high-intensity physical-assault exercise, and the other had not. Participants who completed the assault exercise showed impaired recall and recognition performance compared with the control group. Specifically, they provided significantly less accurate information concerning target critical and incidental target individuals encountered during the scenario, recalled less briefing information, and provided fewer briefing updates than control participants did. Exertion was also associated with reduced accuracy in identifying the critical target from a lineup. These results support arousal-based competition accounts proposing differential allocation of resources under physiological arousal. These novel findings relating to eyewitness memory performance have important implications for victims; ordinary citizens who become witnesses; and witnesses in policing, military, and related operational contexts.

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Performing Under Pressure: Gaze Control, Decision Making, and Shooting Performance of Elite and Rookie Police Officers (2012)

Joan N. Vickers & William Lewinski

 

Publication: Human Movement Science

Gaze of elite (E) and rookie (R) officers were analyzed as they faced a potentially lethal encounter that required use of a handgun, or inhi- bition of the shot when a cell phone was drawn. The E shot more accurately than the R (E 74.60%; R 53.80%) and made fewer decisions errors in the cell condition when 18.50% of E and 61.50% of R fired at the assailant. E and R did not differ in duration of the draw/aim/fire phases, but the R’s motor onsets were later, during the final second compared to the E’s final 2.5 s. Across the final six fixations the E increased the percent of fixations on the assailant’s weapon/cell to 71% and to 86% on hits, compared to a high of 34% for the R. Before firing, the R made a rapid saccade to their own weapon on 84% of tri- als leading to a failure to fixate the assailant on 50% of trials as they fired. Compared to the R, the E had a longer quiet eye duration on the assailant’s weapon/cell prior to firing. The results provide new insights into officer weapon focus, firearms training and the role of optimal gaze control when under extreme pressure.

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Fired Cartridge Case Ejection Patterns from Semi-Automatic Firearms (2010)

William J. Lewinski, William B. Hudson,  David Karwoski,and Christa J. Redmann

 

Publication: Investigative Sciences Journal

During testimony, “experts” often cite that spent cartridge case ejection locations from a semi-automatic firearm indicate the location of the shooter based on the assumption that most spent cartridge cases land to the right and rear of the shooter. The authors of this study investigated whether spent cartridge case ejection locations are an accurate indicator of a shooter’s location. Eight different semi-automatic weapons most frequently used by police officers were used to collect data from eleven different shooting positions. The results highlighted the significant inconsistency of the spent cartridge case ejection locations that occurred across test positions even when several factors including firearm type, firearm position, and ammunition were accounted for. Of 7,670 bullets fired, over 25 percent of the spent cartridge casings landed somewhere other than to the right and rear of the shooter where it is commonly accepted they should land. That pattern inconsistency is significant and demonstrates that determining shooter location from the spent cartridge case alone leads to only a tentative estimate of the shooter’s location.

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New Developments in Understanding the Behavioral Science Factors in the ‘Stop Shooting’ Response (2009)

William Lewinski, and Christa Redmann

 

Publication: Law Enforcement Executive Forum

A law enforcement officer can use deadly force with a firearm in a variety of circumstances. However, once that officer has used deadly force, the microscope of the investigators, his or her department, the courts, and society will focus on the circumstances of the shooting and the officer’s response(s) to those circumstances. Inherent within this investigation will be a close scrutiny on two phases of the shooting. First, the officer’s decision and/or reaction to start shooting and then the officer’s decision and/or reaction to stop shooting. For understandable reasons, in lethal force encounters, the officer’s primary focus is usually on surviving threats to his or her life, and most of the officer’s preparation and training has focused on the officer’s responses that would most likely guarantee that survival. Very little attention if any is focused on immediately stopping shooting when the lethal threat changes—even if stopping immediately was humanly possible.

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The Attention Study (2008)

William Lewinski

 

Publication: Law Enforcement Executive Forum

Perception, or the acquisition of information through the senses, has been a focus of philosophy and psychology for millennia. Phenomenological philosophers recognized that we were not simply passive absorbers of information but actively interact with our environment to perceive, process, and interpret this information. The philosophers’ perspective simply expressed is that there is no such thing as an objective reality. The very act of perceiving is dependent upon the direction and quality of the senses of the perceiver, and this varies on an individual level based on the nutrition, fatigue, experience, interest, etc., of the observer. Further, they questioned whether the very act of observing changed in some fashion the elements of what was being observed. If that were true, it would further distort the reality of that which is being observed. For instance, a cell under a microscope is neither seen nor functions as it would among other cells in a body. The very act of observing changes the dynamics of that which is observed. Subsequently, there was and is no such thing as a pure, objective reality. Similarly, there is no such thing as a pure, objective viewer.

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Pursuit Driver Training Improves Memory for Skill-Based Information (2008)

Jonathan W. Page,  Corey M. Thibeault, Kasee F. Page & William J. Lewinski

 

Publication: Law Enforcement Executive Forum

Police drivers must attend to information from multiple sensory modalities during a high-speed pursuit. This aises an important question: Does training facilitate the shifting of focus between visual and auditory modalities and the subsequent recall of information? The authors tested personnel from the London Metropolitan Police Service to see if various levels of driving training influenced memory recall during an attention-shifting task. Participants were presented standard and police-related memory items while simultaneously attending to distracters. Brain activity was measured to the presentation of the distracters to ensure participants are indeed paying attention to both tasks. The authors found that training did have a significant effect on memory for police-related items. The results are attributed to training because the experimental design ruled out concentration and natural ability as possible explanations..

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A Survey of the Research on Human Factors Related to Lethal Force Encounters: Implications for Law Enforcement Training, Tactics, and Testimony (2008)

Audrey Honig, and William Lewinski

 

Publication: Law Enforcement Executive Forum

To effectively train and fairly evaluate the performance of an officer in a tactical environment, we must first fully understand how the brain perceives and processes information. This article will begin with an exploration of how the brain/mind processes routine information, followed by a discussion of the research on the effects of stress on perception. The brain refers to the actual organ contained in the skull that coordinates sensation and intellect, while the mind refers to consciousness/thought or intellect/memory. For our purposes, however, the terms will be used interchangeably. Common perceptual distortions and mistakes of fact will be identified, and their effect on reaction time will be discussed, taking into consideration the scientific and practical limitations governing human performance. Training recommendations designed to reduce both the rate and range of perceptual and processing errors while decreasing response lag time, or the time it takes to initiate a response, will also be proposed. Finally, improved methods for mining memory will be offered with the goal of increasing the accuracy of incident recall. The information will be presented as objectively as possible. It will be up to the reader to weigh the research, including potential organizational and/or political ramifications, and the pros and cons of any proposed changes to policies or practices.

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Command Sequence in Police Encounters: Searching for a Linguistic Fingerprint (2008)

Julie Vandermay, Dan Houlihan, Liesa A. Klein, William Lewinski, Jeffrey Buchanan

 

Publication: Law Enforcement Executive Forum

The analysis of language and word use is a fledgling area growing rapidly in the field of psychology. Whether the focus of language research is on purported emotions, personality traits, or the context of dialogue, it is apparent that the language we use and the words we choose to use in a given situation can have a significant impact on others. With a general dearth of studies in the area of language use, it is not surprising that language research is almost entirely missing from the field of law enforcement.

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Command Types Use in Police Encounters (2008)

Emily Schwarzkopf, Daniel Houlihan, Kari Kolb, William Lewinski, Jeffrey Buchanan, Angela Christenson

 

Publication: Law Enforcement Executive Forum

Selective attention, commonly referred to in law enforcement as tunnel vision and tunnel hearing, plays a very significant role in an officer’s perception, performance, and memory in a high stress encounter. An aspect of this phenomenon that the Force Science Research Center (FSRC) at Minnesota State University, Mankato, is interested in researching is the officer’s attentional responses and the impact of that on the ability of an officer to effectively multi-task—particularly in a life and death encounter. Clinical investigation has informed us that the emotional response of an officer has a high degree of relevance on the officer’s attention and then on the ability of an officer to both engage in life-saving behavior and simultaneously give meaningful and relevant commands in an attempt to control a threatening subject. The observations have also led us to hypothesize that the more an officer perceives that he or she has control of a situation, the more he or she is capable of giving relevant, meaningful commands. The less control he or she perceives that he or she has over a situation and the more threatening the situation is, the less relevant and meaningful the officer’s commands are as his or her attention becomes focused on the need to engage in life-saving action to stop the threat. This article is the first in a series that FSRC will present as this phenomenon is explored and the most effective types of responses and the most effective commands for officers in high stress, life-threatening encounters are sought.

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An Examination of Police Officer Mental Chronometry (2006)

Jeffrey Bumgarner, William Lewinski, William Hudson, Craig Stapp

 

Publication: The Scene

Every year, dozens of suspicious deadly force encounters involving police officers who have shot suspects pit the reputation of well-regarded and highly trained officers against physical evidence which suggests the officers acted maliciously. In particular, suspects are sometimes found to have been shot in the side or back despite the protestations from the firing officers that they had perceived frontal threats from the suspects. While officer malice is one possible (and sometimes probable) explanation for such shooting incidents, other explanations may also exist. This article reports the findings of a 4-experiment study involving 102 police officers in a major police department in the Southwestern United States. The results of the study demonstrate that many variables go into an officer’s ability to react to stimuli in a timely man- ner and that even in laboratory conditions, there is ample time for the threat picture to change before an officer can either turn on, or turn off, a decision to react by firing a weapon.

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Dr. Bill Lewinski

© 2017 Dr. Bill Lewinski