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Back to Archives | Back to October 2012 Contents 

The Mental Edge: Effective Cognitive Processing in Law Enforcement

By Matthew J. Sharps, PhD, DABPS, FACFEI, Professor, Department of Psychology, California State University, Fresno, California

ost of the contacts officers and commanders have with psychologists deal with issues of mental health, such as fitness for duty and preemployment. The police psychologists themselves are generally clinical or counseling psychologists, with training in the relevant areas.

There is, however, another area of law enforcement psychology: The emerging field of forensic cognitive science. The practitioners are generally researchers rather than clinical psychologists, and they deal with issues directly pertinent to officer success, safety, and survival. The processes of thinking and memory in officers, witnesses, and perpetrators are the focus of this field. In view of the enhanced operational tempo of modern law enforcement, the information provided by this scientific approach is essential to commanders at all levels.

With all the demands on chiefs’ time, why is it worthwhile to develop knowledge of the role of cognitive processes in officer effectiveness and survival? The answer is simple. Under the physical and mental stresses characteristic of modern law enforcement environments, officers and commanders operate within the province of their training. If this training is based in sound cognitive principles, the probability of success and survival will typically be enhanced. If not, in the worst case, officers will not go home at the end of their shifts. The exemplary work of Colonel Grossman demonstrates this clearly,1 and the author of this article has discussed the field in depth for officers and commanders in his own recent book Processing Under Pressure.2 Most of what follows derives from the most important information presented and discussed in this work.

Training to Stay Alive

In the high-tempo world of modern law enforcement, violence against officers is regrettably more common than in the past. A variety of cognitive processes operate in these situations. An understanding of these processes is critically important for officers in the field and especially for their chiefs and commanders.

Consider the phenomenon of tunnel vision, in which an officer under stress may focus on central stimuli, such as an armed individual to be apprehended. This focus may be achieved at the expense of more peripheral elements of the tactical situation. If one of these elements is an armed friend of the suspect, there is a good chance that the officer will be shot.

Tunnel vision is frequently seen in training scenarios, even with experienced, veteran officers. Consider a training simulation in which shots are fired at one end of a hallway. The shooter is out of sight of officers in training, who enter the simulation at the other end. The trainees—veteran officers—run down the hallway to reach the scene of the shooting.

The problem is that the simulation includes mock improvised explosive devices (IEDs) distributed liberally on the floor of the hallway. They are in plain sight but are frequently completely ignored, even by veteran officer trainees. Officers literally kick IEDs out of their way or charge past them as if they are not there in their haste to get to the location of the shooting.

This is the effect of tunnel vision. Arousal-based tunnel vision, in the scenario described above, creates a focus on what trainees perceive to be the most important part of the scenario: The shooting. This focus is so profound that trainees may fail to notice explosive hazards, perfectly visible and literally underfoot. This, of course, was observed in training; in the more stressful environments of real-world law enforcement, the officers would have died as a direct result of the tunnel vision involved.

Consider another training evolution a building entry, in which officers are so focused on their own tactical actions that they fail to notice a sniper standing in plain sight within 50 feet. In this case, the sniper peppers the wall of the building with paintball rounds. These slam repeatedly into the wall, within one yard of one the trainee officers; the trainees do not notice the rounds crashing into the wall near their own heads.

So, strong tendencies toward tunnel vision exist in the brain whenever that brain is placed under tactical stress. Therefore, realistic training must be provided to fight against it. This training should be provided in a variety of realistic environments, reflecting the reasonable possibilities that officers may encounter in the field. In the case of the IED evolution discussed above, the author’s research group has used cognitive principles to develop training specifically to detect IEDs placed both centrally and peripherally in a given scenario. The use of these principles has enabled the group not only to defeat all five types of error that typically occur in IED situations but also to double trainee performance, both in speed and accuracy, in the detection of IEDs.3

The cognitive processes exemplified by tunnel vision are especially important today, because, under the stresses characteristic of modern law enforcement tactical situations, individuals may operate on so-called automatic pilot. Under the stress of combat, blood flows to the muscles, reducing the oxygen and nutrients available to the most flexible parts of the brain. This means that tactical innovation is necessarily reduced, under the conditions in which it is most needed, and officers revert to the most basic levels of their training—whatever that training might be. This is in fact the physiological source of tunnel vision, in which diminished cognitive resources focus on what the officer perceives to be the most important part of a given situation, perceptually neglecting the rest.

An infamous and tragic case of this phenomenon was seen in the 1970 Newhall incident in southern California, in which well-trained officers of the California Highway Patrol (CHP) were killed by heavily armed assailants.4 Among the many terrible lessons derived from this incident was the fact that the officers tended to respond to the dangers of the firefight with the exact motions they had learned in training, regardless of whether these motions were appropriate to the given situational evolution or not. The best known example of this occurred in the case of one officer who had expended all six rounds from his revolver. He dumped the spent shell casings into his hand, and then took the time to put them in his pocket, having been trained to pick up his brass in practice on the firing range. The wasted time allowed one of his assailants to flank him and to kill him from behind.

This range training had inadvertently and tragically surfaced, on automatic pilot, in combat: In the middle of a firefight, the officer apparently stopped to pocket his spent shell casings. The CHP ultimately, and admirably, benefited from the terrible lessons learned by changing its training protocols accordingly. However, the Newhall tragedy serves to illustrate the critical importance of the evaluation of every element of training. Under high-stress circumstances, officers are likely to revert to their most ingrained and habitual patterns of behavior.

How should training be constructed to avoid these disasters? Recent research in forensic cognitive science provides an answer, in the so-called holy trinity of principles to govern training. Training must of course be conducted as realistically as possible, with reference to the spectrum of situations to which an officer might reasonably be expected to respond. However, beyond this, there are three specific elements of training which promote success:

  1. Training should provide a prior framework for understanding. The specific purposes, utility, and scope for which a given evolution is appropriate should be made clear to all trainees prior to exercises in the given skills.
  2. Training should be explicit. Officers should not have to imply or infer the circumstances under which the training may be useful. The specific skills—and the specific circumstances under which they may be applied—should be explicitly clear to trainees prior to practice exercises.
  3. Training should initially be feature-intensive in nature. Trainers should initially provide a step-by-step breakdown of the skills involved in any training evolution. They should provide explicit guidance concerning each feature of the skill set in question, together with its use in responding to the reasonable spectrum of eventuality which officers may encounter in the field. The skills involved should be explicitly understood by trainees, as a prior framework for understanding, prior to practice exercises.

With a prior, explicit, feature-intensive framework in place, practice exercises will be typically enhanced in effectiveness, ultimately resulting in the smooth sets of responses necessary for rapid response in the field.

A Case Study

An excellent example of this type of cognitively based training, and of its application in the field, is found in the response of a California police commander to a situation involving deadly force when he was a young officer.5 The commander had responded to a domestic situation. As he talked with the victim at her door, he was of course focused on the central aspects of the case. The victim stated that her attacker, her husband, had left the area.

In his central focus on taking her statement, the commander, by his own report, experienced tunnel vision. He did not notice the husband, squatting in his vehicle, approximately fifty feet away on the periphery of the scene. Even though the commander had the car’s description and tag number, he did not at that time see the vehicle or the assailant; the human nervous system’s tendency toward tunnel vision, toward a focus on the situation in the center, precluded his observation of the periphery.

Another officer arrived. At the commander’s request, he began to search the area. The second officer found the husband, who exited the vehicle and became aggressive. The commander approached, coordinating his movements with those of the other officer. At this point, the suspect raised a weapon and fired, wounding the second officer. Then the suspect turned to shoot the commander.

The commander did not immediately attempt to return fire; to do so, since the assailant was already shooting, could have resulted in his death. Rather, the commander took cover behind the other officer’s patrol car; he leaped behind it without thinking at all. From this cover, he returned fire, killing the assailant.

Why did the commander, unlike his fellow officer, take proper cover, thus bringing the deadly encounter to a successful conclusion? He credits his ability to do this, in the middle of a firefight at a range of 10 feet, to a training situation two weeks earlier. The training officer had repeatedly required the trainees to fire twice at a target and then jump behind available cover, an appliance carton placed on the range. This training provided a prior framework for understanding the situations to which the evolution was appropriate, was explicit in its utility, and provided feature-intensive instruction in the motor skills involved. This was followed by repetitions of the evolution, “over and over” in the commander’s words, until the relevant skills blended into a smooth gestalt. This enabled him to repeat the motions involved perfectly, even under tactical stress.

Again, under such conditions, the officer will tend to revert to his or her most ingrained habits. In some cases, such as that of the Newhall incident, this may lead to disaster; but because of the cognitive nature of the commander’s training, to which, in his words, he had been “particularly attentive,” his ingrained habits resulted in his own survival and a successful termination to the action.

The case of this police commander strongly highlights the need for versatile, realistic training, which is explicit and feature-intensive in nature and provides a prior framework for understanding. The motions of such training become the automatic pilot—whether good or bad. Good habits result from talented officers’ exposure to prior-framework, explicit, feature-intensive training, followed by extensive practice with the reasonable spectrum of eventuality to which those officers will be exposed. Bad habits, frankly and simply, may get the officers killed.

Memory under Tactical Conditions

The commander’s performance under these conditions, and his subsequent rise through the ranks of his department, mark him as an officer of superior ability. However, even at his level of competence, this commander reports no memory of the events subsequent to the shooting. On his return to his station, he stated that he had no memory even of his locker combination.

Such memory anomalies are characteristic of the stress of modern tactical situations, and they have enormous implications for modern law enforcement environments. Consider the following hypothetical situation, compiled from several actual, and devastating, real-world cases. A male officer is confronted by an armed suspect who is under the influence of crack cocaine or methamphetamines in the diminished visual conditions of partial darkness. The officer, in fear for his life, fires an entire magazine from his service weapon. Rounds strike the suspect, but are not disabling; the wounded suspect continues to attack. The officer therefore ejects the spent magazine, performs a combat reload of an additional magazine, and fires three rounds to subdue the suspect.

In the typically chaotic aftermath of the shooting, surrounded by fellow officers, spectators, and the media, the officer checks the magazine to ascertain the number of rounds fired. There are, of course, three rounds expended, so the officer encodes the number three in memory. Later, still in a state of fatigue while writing his report of the incident, the officer reports three rounds expended. In fact, seventeen rounds were actually fired, as becomes abundantly clear in the initial department investigation, the internal affairs query, and in court. The verdict is obvious: The officer lied, in a flagrant integrity violation that costs the officer’s career and, very probably, his freedom. He simply does not understand it; the memory of three rounds fired is so clear. In a later interview with a police psychologist, the officer, obviously in a state of fear, asks earnestly if he has “gone crazy.”

So what happened? Which was it? Was the officer a liar, or crazy, or possibly a crazy liar?

Very probably, none of the above. Well-rehearsed sets of motions, such as those involved in drawing and firing a service weapon, are generally processed as motor programs to a major degree in the cerebellum, an older part of the brain that communicates rather poorly with the more conscious areas of the brain that deal with awareness and assessment. Normally, of course, we are relatively aware of our motions anyway; but in the case of the fight or flight response characteristic of all humans—for even the most highly trained officers under tactical conditions—this monitoring and awareness are limited, as we saw earlier in the case of tunnel vision. The reason is that in combat, with an increased heart rate and the corresponding dilation of blood vessels, blood is distributed throughout the body—blood that would normally be available for the energizing of the prefrontal cortex, which is the part of the brain most involved in conscious thought and in the monitoring of our behaviors.

This means that the combat reload, an automatic process basically arising from the back of the brain, was effectively never noticed by the front of the brain, which was necessarily diminished in its efficiency.

The officer was neither lying nor mentally ill. He made a mistake, one which is entirely explicable within our current understanding of the cognitive functioning of the brain under pressure, even in the best trained officers.

This entire situation, disastrous for the officer and for the credibility of his department, could have been prevented by a more thorough, immediate investigation of the physical facts, at the scene of the shooting, by an officer or supervisor who had not just been though a gun battle, and whose prefrontal faculties were therefore operating at normal efficiency. However, in order to know that such an investigation was even necessary, police commanders would need the relevant facts about the nervous system and about cognitive processing under pressure. Without these facts, this incident would prove catastrophic for all concerned.

Cognition and Command

The cognitive principles that apply to officers and witnesses also apply to chiefs and commanders. This can be readily seen in analyses of well-documented military situations.

Consider the infamous Battle of the Little Bighorn, in which elements of George Armstrong Custer’s Seventh Cavalry were effectively annihilated by a vastly superior force of Sioux and Cheyenne warriors. The basic facts of this battle are well known to virtually everyone. Less well known is how Custer came to this end; the relevant principles are, not surprisingly, available through an examination of cognitive processing under the extreme pressures of that particular war.

Custer was already under pressure from a variety of political problems; many of his senior officers despised him, and he was at the time actually embroiled in a feud with the President of the United States, Ulysses S. Grant. Although Custer intended to take advantage of the element of surprise, it was known that the Sioux and Cheyenne were entirely aware of his presence (they had found a U.S. Army breadbox on the enormous trail left by his columns). They knew he was there. On climbing a high hill overlooking the Little Bighorn from a distance of some miles, his scouts had located the gigantic American Indian camp, and could see it clearly. Custer, on climbing the same hill, was unable to see the village at all. Knowing that he faced several thousand potential adversaries, he divided his command (leaving the bulk of it with the officers who hated him the most) and attacked with only 212 men; and as he saw, effectively, all the Sioux and Cheyenne warriors in the world surrounding and charging at his tiny personal command, his final words were apparently “Hurrah, boys, we’ve got them!”

How was this possible? Was Custer stupid or perhaps insane? His earlier, highly successful campaigns in the Civil War belie these simplistic explanations. However, he was under extreme stress, as are many chiefs and commanders in law enforcement today. His political difficulties with his superiors and subordinates formed a chronic source of chaos familiar to those who serve in many military and law enforcement agencies. His hyperfocus on attaining a victory to atone for some of these problems, perhaps similar to the hyperfocus on range training that occurred in the Newhall incident, may have resulted in his ignoring seemingly extraneous details such as the breadbox—details that in fact proved to be crucial. Custer’s tactics at the Little Bighorn were similar to those he had used in a previous success, at the battle of the Washita River. Under stress, he reverted to reliance on his experience, even though, as was the case at Newhall, the experience was not tactically relevant to his new situation. His hyperfocus on victory, at the expense of perceptual reality, was so extreme as to account for the disastrous, if ludicrous, “Hurrah, boys, we’ve got them!” As to his inability to see the village, a clear analogue is apparent in the officers in the IED training situation described above, whose focus on the shooting at the end of the hall resulted in their kicking IEDs out of the way, in a complete failure to see or notice them.

Chiefs and commanders might legitimately wonder whether a battle of the American West in 1876 is truly relevant to their own missions in the modern world; but consider the more modern 1993 incident in Mogadishu, Somalia, which resulted in the infamous Black Hawk Down debacle.6 In that situation, as the author has discussed in detail elsewhere,7 virtually identical cognitive factors were in operation. Political problems had placed commanders under great stress. The hyperfocus on the hopedfor success of the mission (that is, the arrest of lieutenants of the Somali warlord Aidid) was so profound that the forces deployed were inadequate to the potential military situation, as occurred with Custer and his 212 men. The element of surprise was crucial, as it was at the Little Bighorn. Yet surprise was lost. The Somalis demonstrated their knowledge of U.S. intentions by burning huge piles of tires, the black smoke columns of which were a signal to gather in great numbers to repel the U.S. attack. This was observed and reported by the helicopter crews in the first wave of the assault. However, just as Custer ignored the breadbox, the commanders at Mogadishu ignored the gigantic columns of smoke. The attack went on exactly as planned, with no modification for the changed circumstances. Numerous casualties were the result.

From a noncognitive standpoint, the Little Bighorn and the battle of Mogadishu seem very different. The one involved horses, the other helicopters. One occurred on the open plains of the American West, and the other in a densely populated African city. Yet from the standpoint of cognitive processing, the two situations possess critical and disastrous commonalities. These commonalities, if recognized, could have prevented the high casualty rates of both situations, through prior, explicit, feature-intensive training in the cognitive principles which govern the responses of both officers and commanders.


The enhanced operational tempo of modern law enforcement requires a modern edge. Under tactical conditions, officers and commanders can expect to revert to their training, to their most ingrained habits and patterns of behavior. These patterns can be optimized for survival and success through cognitive-based training. Such training provides prior frameworks for understanding, is explicit, is initially feature-intensive in nature, and gives rise to practice that results in smooth series of responses to the reasonable spectrum of tactical possibilities which may confront modern law enforcement agencies.

These principles have already proven their worth in such areas as training for IED detection, in which single training evolutions have been shown to result, literally, in the doubling of performance.8 The incorporation of modern forensic cognitive science into modern law enforcement provides a substantial edge for the challenges apparent today and will promote the safety, success, and survival of officers, commanders, and chiefs. ?


1Dave Grossman and Loren W. Christensen, On Combat: The Psychology and Physiology of Deadly Conflict in War and in Peace (Milstadt, Ill.: Warrior Science Publications, October 1, 2008).
2Matthew J. Sharps, Processing under Pressure: Stress, Memory, and Decision-Making in Law Enforcement (Flushing, N.Y.: Looseleaf Law Publications, 2010).
3Matthew J. Sharps et al., “Finding IEDs before They Find You: The SMOKE System of Training for Hazardous Device Detection,” Forensic Examiner 19, no. 1 (2010): 48–59.
4Jim Holt, “Newhall Incident: The Day That Shook Our Valley,” Santa Clara Valley Signal, April 6, 2008, (accessed August 23, 2012).
5Sharps, Processing under Pressure.
6Articles by Mark Bowden, “Blackhawk Down,” Philadelphia Inquirer, November and December 1997, (accessed August23, 2012).
7Sharps, Processing under Pressure.
8Sharps et al., “Finding IEDs before They Find You.”

Matthew J. Sharps can be reached at

Please cite as:

, "The Mental Edge: Effective Cognitive Processing in Law Enforcement," The Police Chief 79 (October 2012): 100–104.



From The Police Chief, vol. LXXIX, no. 10, October 2012. Copyright held by the International Association of Chiefs of Police, 515 North Washington Street, Alexandria, VA 22314 USA.

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