This article was originally published in The ILEETA Journal | 2022 Winter Edition Volume 12 Edition 4 and is reprinted with permission.
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In police use-of-force cases, understanding human factors allows us to identify the psychological, physiological, and environmental conditions that can influence decision-making, performance, and even memory. The goal is to prevent agencies, courts, and communities from developing unrealistic expectations of the perfectly imperfect officers involved in critical incidents.
The Force Science Consulting Division continues to be involved in many of our country’s most high-profile police use-of-force cases. Understanding that human factors can influence decision-making and performance generally is not enough. Courts require that force encounters be evaluated from the perspective of a reasonable officer. This means judges, juries, and review boards must not only understand how human factors can influence an officer’s perception of a critical incident. They must understand how a police officer might reasonably interpret that experience as they engage in threat assessments, problem-solving, and physical responses. Enter the police practice expert.
Police Practice Experts
When civilians (e.g., civilian review boards, judges, juries) evaluate police use-of-force cases, experts are required to explain how training, education, and experience inform police tactics, threat assessments, and use-of-force decisions. These police practice experts not only identify the relevant facts of a case but also explain the reasonable inferences that an officer might draw from those facts—inferences that are often counterintuitive and would not likely occur to the ordinary judge or juror.
Although police practice experts are increasingly found with advanced degrees in law, human factors, psychology, decision-making, and medicine, most police practice experts and use-of-force experts are non-scientific professional practice experts whose knowledge and opinions are based on professional education, training, and experience—and not scientific research or testing. This distinction is critical in whether and how these experts will be allowed to testify in court.
Police practice experts are typically police officers or former police officers who enhance their experience with continuing education, conference presentations, and trade publications. These sources of information summarize relevant police-related scientific research, sociological research, professional practice, and legal and tactical considerations. Although some police practice experts may immerse themselves in peer-reviewed journals or conduct independent research, this appears to be the exception.
Police practice expertise is often the product of real-world experience and lessons shared through academy training, formal field training, in-service, and informal discussions.
Contemporary police training, investigative strategies, and police practice increasingly enjoy the support of scientific literature. However, it is not expected that peer-reviewed studies or empirical analyses exist to support every industry practice or custom. Even where relevant research exists, not every police practice expert will be aware of the study or literature.
Police Practice Experts and Human Factors
Police practice experts, whether they develop training, conduct training, write policy, investigate the use of force, or continue to provide police services, must understand the potential influence of human factors.
Understanding the potential influence of human factors is necessary to explain why police do what they do. It does not imply scientific expertise in the underlying psychological or physiological processes driving human factors. This lack of scientific expertise does not imply a lack of qualification—quite the opposite.
Police practice experts are frequently more qualified to explain human factors in the context of policing in ways that the typical scientific expert, attorney, and academic researcher is not.
Police Practice vs. Scientific Experts
To understand the distinction between police practice experts and scientific experts, it may be useful to consider the following examples.
Example 1: Action and Response
It is well-settled that even if an officer has their gun out and directed toward a suspect, that suspect may be able to present and fire a gun before the officer can even perceive the attack (let alone respond to the attack). Experts are often needed to explain this action/reaction phenomenon to new police officers, attorneys, and to ordinary jurors. It may seem intuitive where an officer “has the drop on the suspect” or is “covering the suspect” with their gun, that the officer has the advantage. Ordinarily, they do not.
Police Practice Experts
Police practice experts may have first learned this officer-safety lesson simply because their academy trainer told them that “action beats reaction.” This lesson may have been reinforced through realistic role-playing training or simulations, during which the expert or others were repeatedly “shot” by suspects despite covering those suspects with their training firearms. Initially developed through training, countless real-world deadly-force encounters continue to support this expert understanding of human dynamics.
Police trainers who have learned that merely “covering” an armed suspect may be insufficient, will develop tactics, training, and use-of-force strategies that reflect that reality (e.g., use cover, create distance, physically control the suspect, or preemptively use force). These experts can be used to explain the reasons behind these police practices to those responsible for ensuring police accountability.
Scientific experts have also observed that action will frequently beat reaction. In clinical studies, scientific experts have investigated an officer’s ability to effectively respond to armed threats. In these studies, researchers observed that, even in ideal lab settings, an officer with their gun drawn and directed toward the suspect may still average over .80 seconds to respond to a “threat.” On the other hand, the “suspect” is able to initiate and complete their armed assault in an average of .25 seconds (some much less).
Although scientific research (like that mentioned above) may support a police practice expert’s opinion, it is usually not the scientific research that created the expertise. Scientific research can validate what police practice experts have learned from experience, but it is unlikely to fully-inform their expert opinions.
Beyond the Lab: Real-World Expertise
The scientific experiment described above might present a useful example of a “best case” lab scenario and even prove an important tool for educating a jury. However, police practice experts will likely have much more to say on the subject.
Experience with real-world force encounters and realistic training scenarios may have taught police experts that an officer is likely to take much longer than .80 seconds to respond to a deadly attack. This is because, an officer’s attention is almost always divided, they are multi-tasking, the attack “start” time is often uncertain, and the appropriate response may not be obvious. In other words, officers in real-world force encounters might not even recognize the attack, let alone respond to it in 0.80 seconds.
Example 2: Fail to See
Another example that may be useful in explaining how police practice experts may be distinguished from scientific experts can be found in the areas of perception, cognition, and memory.
Police Practice Experts
A police practice expert may have seen hundreds of cases wherein a witness or victim’s memory was inconsistent with objective video evidence. This occurs in the absence of a motive to lie and with such frequency that it has become a part of investigative training to expect these inconsistencies.
A police practice expert will recognize that even the most honest witness can misremember details of an event. Experts might know through experience that a person’s ability to recall events may be impacted by the dynamic and traumatic nature of the event. These experts might be trained to identify the potential influence of these human factors in a case, without being able to conclude with any degree of medical certainty whether or how these human factors influenced a specific individual.
Instead, investigators, and those who later evaluate use-of-force cases, are trained to recognize that failing to remember details or misremembering details is not definitive proof of deception. This understanding drives interview strategies and informs the evaluation of statements provided during use-of-force (and other criminal) investigations.
Scientific research into a person’s ability to accurately perceive or remember the details of an event is extensive. Police practice experts ordinarily will not have conducted this research but will consider and rely on the research of scientific experts to shape their investigative strategies and evidence analysis.
For example, Dr. Marc Green is a human factors expert with over 45 years of research experience. Dr. Green has authored over 100 publications in the areas of vision, visual search, attention, perception, reaction time, and human cognition. He is the principal author of the book, Forensic Vision: With Applications to Highway Safety.
Although Dr. Green is a human factors expert with extensive experience investigating traffic accidents, he is an excellent example of how peer-reviewed human factors research from one industry is summarized and applied to police practice.
For example, Dr. Green applied his perception and cognition expertise to police practice. To educate the law enforcement industry, Dr. Green published his analysis in various police trade magazines, which included the Police Marksman and Law and Order (See “Is It A Gun? Or Is It A Wallet?’” Perceptual Factors In Police Shootings of Unarmed Suspects,” Police Marksman, July/August, pp 52-54, 2005; see also “Proper Eyewitness Identification Procedures,” Law and Order, pp. 195-198, October 2003).
Learning from the Experts
Top police practice experts are trained to consider the potential influence of human factors in police use-of-force decision-making. They understand how attention and perception factors might influence threat assessments and responses.
Trade magazines, like those utilized by Dr. Green (i.e., Police Marksman, Law and Order), are among the types of sources relied on by police practice experts to inform their practice and reach their conclusions.
Although peer-reviewed research and empirical studies may not capture the breadth of police practice expertise, they can provide valuable scientific evidence to help explain why officers do what they do. They can provide objective support for the reasonableness and reliability of the police practice experts’ opinions.
Still, when it is necessary to explain the psychological, neurobiological, or physiological processes that cause a human performance effect, or, if it is necessary to determine whether a specific individual experienced that effect, courts will be reluctant to qualify police practice experts for that purpose. Instead, relevant scientific experts should be engaged.
On the other hand, when it is necessary to explain why officers engage in specific tactics, what principles are generally accepted in law enforcement, or what factors police consider when training, investigating, or engaging in force encounters, police practice experts are often the most qualified and useful for answering those questions.