What The New Study Of Shootings Of Unarmed Suspects Means To You (Part 2)

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2 of a 2-Part series

Editor’s Note

In Part 1 we reported on a ground-breaking new study by researcher Tom Aveni on why and under what circumstances officers shoot suspects who end up not to be armed. Here we offer some of the significant implications of Aveni’s findings. Aveni is founder of The Police Policy Studies Council and serves on the national advisory board of the Force Science Research Center at Minnesota State University-Mankato.

As we detailed in Part 1, Tom Aveni’s unique study confirms that shootings of unarmed subjects during police confrontations typically do not result from racial bias by the officers involved. Instead, such controversial, “mistake-of-fact” events occur because certain “compelling” behavior by suspects leads officers to believe they are about to be attacked and, under tremendous time pressure, they shoot “preemptively” to defend themselves, before the presence of a deadly weapon can actually be confirmed.

Aveni’s findings about the dynamics of these situations have important implications for officers, trainers, shooting investigators, administrators, and police defense attorneys. In an exclusive interview with Force Science News, he explained some of the practical conclusions to be drawn from his data. For a comprehensive report of Aveni’s study, view “A Critical Analysis of Police Shootings Under Ambiguous Circumstances.

Officer Safety

One of the interactive videotaped scenarios Aveni used in testing more than 300 officers from 6 law enforcement agencies involves what looks like a mugging-in-progress that a patrol officer happens upon late at night. The apparent perpetrator suddenly spins toward the camera (the “responding” officer) with something in his hand. Often in the testing he was shot-although the object he held in some scenarios was revealed to be a police ID wallet with metal badge.

The lesson could be life-saving: If you get involved in an arrest while off-duty or working undercover and are challenged by an arriving officer who doesn’t know you’re a cop, react with great caution and no sudden, energetic moves. Aveni’s research established that the unarmed subjects most likely to be shot during his study were those who turned toward an officer abruptly and quickly, sank into a crouch, and thrust clenched hands up from waist level as they spun around.

Hand posture is critical. “Even with rapid movement, an open hand is perceived as much less threatening because it is almost immediately recognized as empty and thus weaponless,” Aveni says. “A clenched hand exudes ambiguity. It is much less likely to be view innocuously, especially in the context of possible criminal activity.” In debriefs after the testing, more than 70% of the officers said their decision to shoot was influenced by a suspect turning toward them with “something” in his or her hand.

Most important: follow the responding officer’s directions. “Noncompliance with verbal commands,” Aveni says, “was one of the most consistent factors” cited as a precursor to a shooting decision. “From that frame of reference, potentially aggressive actions made subsequently by a suspect would understandably be perceived as threatening.”

Dr. Bill Lewinski, executive director of the Force Science Research Center, agrees. “In the friendly-fire cases I’m familiar with, noncompliance was the primary factor in an off-duty or undercover officer getting shot.

“In a sense, the officer becomes a victim of a treacherous psychology. Although the responding officer is not aware of the plainclothes officer’s status, the challenged officer is thinking of himself as part of the law enforcement team. In that mental state, he may ignore commands because he does not perceive them as relevant to someone ‘on the same team.’

“To guard your safety in such a situation, you need to consciously force yourself to view the setting from the perspective of officers arriving with little concrete information.”


Officers from the best-performing agency in the study shot unarmed subjects 24% of the time. The other agencies had “frequency” scores of nearly 40% or more, with participants from one agency shooting nearly half of the unarmed suspects they confronted in the scenarios. “These distinct differences,” Aveni states, “seem directly attributable to training.

“The agency with the lowest percentage of officers shooting unarmed suspects apparently had the most rigorous scenario-based training regimen. Virtually every participant from that agency had been through one or more force-on-force training sessions in the previous 12 months. Scenario-based training was evident in the other departments, too, but it seemed much more intermittent. That’s the only factor that clearly stood out from all others.”

“The role of training cannot be emphasized enough,” Lewinski stresses. “The more practice an officer has, the faster he or she is able to jump to important elements of a situation and read them accurately. The highly trained officer knows what to look for amid a situation that may seem chaotic to lesser-trained ones. This includes better anticipating what a suspect’s movements will be and more quickly determining what reaction is necessary.

“Good training also produces better emotional control. The highly trained officer tends to make better decisions because he can focus on what he needs to do rather than on reacting impulsively or emotionally, such as recoiling or freezing up from fear.”

Even within the confines of the study, Aveni says, repeated exposure to challenging scenarios seemed to have an impact. “Participants were more likely to shoot in their first scenario than in their second, and more likely to shoot in the second than in the third, even though the scenes were randomly sequenced, with no consistency in the apparent crime depicted or in the order in which armed or unarmed subjects were presented.

“There are serious training implications in this since officers seem to begin to become a bit less impulsive with more scenario exposures.”

In analyzing videotapes made of officers’ responses, Aveni noted other issues that, as a trainer, you may want to evaluate in your own program.

A vertical barricade was provided for officers to use as “cover” while addressing the testing scenarios. Most of the officers took advantage of it, but “there was a wide degree of variance in how early or late in each scenario they elected to use cover and to what degree they used it effectively. Many participants exposed far too much of themselves” from behind the barricade.

Lewinski observes: “Training needs to place more emphasis on teaching officers how to make better use of cover and also on how to assess cover earlier in their contacts. In the midst of a life-threatening action-reaction incident is not the time to start thinking about cover.”

“Many participating officers were seen ‘covering-down’ on suspects with their muzzles pointing directly at ‘center mass,’ ” even though they had not yet made a decision to shoot. “This may diminish reaction time by about one-tenth of a second,” but it produces “serious trade-offs” that bear consideration, says Aveni, a firearms expert who has trained more than 12,000 law enforcement and military personnel.

“A handgun presented to eye level occludes vision of almost everything from the suspect’s sternum down,” he explains. “A suspect’s hand and arm movement are then difficult to impossible to discern. There might be serious threat identification issues with this approach.

“Also by truncating reaction time by elevating the muzzle before committing to fire, you also truncate the amount of time available to stop an erroneous ‘threat reflex’ impulse. So truncated reaction time can be a double-edged sword.

“Recent trends in active-shooter training have led to SWAT tactics trickling down to patrol officers, including the ‘muzzle-dominance’ technique. But we need to remember that this runs contrary to the universally embraced firearms safety protocol of never pointing your weapon at anything you’re not willing to destroy.”

Aveni also advises that the currently popular concept of “stress inoculation” in training be “approached with caution. A disproportionate number of ‘aggressive’ training scenarios may begin influencing reactions in officers akin to ‘fear-biting’ in K-9s.

“Scenario-based training should be geared toward ‘conflict resolution,’ not just gun-fighting skills. It should proportionately reflect the duties and conflicts your officers are most likely to encounter on the street. You may not want your officers to be ‘warriors’ per se, but they must be rational decision-makers.”

Lewinski adds: “A vital emphasis of stress inoculation must be on developing emotional control and better decision-making, not just on improving physical performance skills. If that isn’t at the core of your program, you’re missing the key value of this type of training.”

Departmental Policy

“Policy has been much touted as a means of moderating undesirable behavior,” Aveni points out, but his research suggests that “it is investment in training that yields the best results.” The agencies in his study showed wide differences in the proclivity of their officers to shoot unarmed subjects, yet there generally were “no substantive differences” in their policies regarding use of deadly force.

One agency had a restriction others did not. That department requires its personnel to complete a use-of-force report whenever they unholster their handguns. Some officers from that agency “literally waited to draw until they came under fire” in scenarios where the offender shot at them. “A common response in debriefing younger, less experienced officers was that they were concerned about having their personnel files reflecting frequent usage of force when in reality ‘force’ was never used,” Aveni says.

It’s important to note that while that attitude has “demonstrable occupational safety implications,” Aveni’s research established that their slowness to unholster “didn’t seem to influence the overall judgment” of that agency’s officers. As a group, they had the second highest rate (44%) of shooting unarmed suspects.

Aveni observes: “Even the best intentions have demonstrable occupational safety implications.”

Aveni believes his study results support the “almost universal embrace of the ‘imminent threat’ standard in deadly force policies,” in contrast to the more restricting and currently less popular “immediate threat” standard. However, he expresses concern that under pressure to diminish the frequency of shootings, policy-makers may be tempted to unreasonably tighten the limits of “may-shoot” situations.

Given the prevalence with which officers in the study “found themselves firing at suspects only after the suspect had already turned and fired at them,” Aveni suggests that a “practical and altogether reasonable interpretation” of what an officer might do when, for instance, confronted by a noncompliant robbery suspect, would be to preemptively shoot as the suspect initiates a turning motion toward the officer.

“This will likely be construed as ‘controversial’ in some quarters,” he admits, “but this study’s findings certainly suggest that such latitude is both reasonable and necessary” for an officer’s protection.


The study offers some perspective on the current “raging controversy about whether officers should be permitted to view dash-cam video of their incident before being compelled to provide an oral or written statement to agency investigators,” Aveni says.

In his project, participants could review their videotaped responses before completing a debriefing form. All wanted to see the footage in which they had used deadly force, but they were typically less interested in revisiting encounters in which they did not shoot.

Interestingly, “when they did not review a video replay of their performance, they usually had difficulty remembering many of the situational and behavioral elements that had been embedded in the scenarios,” Aveni says. This resulted in their incompletely answering questions on the debrief form that were linked to important elements in the scenarios.

“At the time they were ‘confronting’ suspects in the scenarios, they usually had to make their shooting decisions in less than one-third of a second,” Aveni says. “They had difficulty remembering everything they’d been exposed to in such compressed, intense time periods” unless they had a chance to see the action replayed in a calmer setting.

“We might assume that what an officer is able to process consciously and then recall unaided may be a mere fraction of what he or she has processed subconsciously. Obviously, there are implications in this for real-life officer-involved shooting investigations.”

Indeed, Lewinski says, this is why FSRC supports officers being shown videotape from dash-cams and Tasers and also returning to the scene of shootings with their attorneys to experience walk-throughs, “provided that the goal is to impartially mine the officers memories and not try to entrap them with what they can’t recall.”

A significant number of participants said that the time of day or lighting conditions depicted in the scenarios may have played a role when they decided to shoot, Aveni notes. By design, all test scenarios were filmed under low-light conditions “to increase realism and incident ambiguity.” To what extent an officer in a troublesome confrontation “can accurately discriminate a handgun from a cell phone, flashlight, or wallet held by a suspect at night is a source of concern,” Aveni says.

He recommends that investigators “seriously consider taking detailed light measurements” when a low-light officer-involved shooting has occurred because the amount of illumination available “may have a direct bearing on an officer’s visual acuity during an extreme encounter.”

Officer Defense

Aveni hoped from the beginning that his study would help to better define how a “reasonable officer” might act in uncertain circumstances that result, ultimately, in the shooting of an unarmed individual. With the data now in and minutely analyzed, he believes his findings do just that and that they may “radically alter the manner in which police use of deadly force is examined in the future” by review boards and in court in many “contentious” shootings.

“The officers and agencies that participated in this research are representative of good law enforcement professionalism. The officers-reasonable men and women-were placed in the kinds of situations from which mistake-of-fact shootings commonly evolve.

“The results have great exculpatory value. They clearly identify the variables that prompt officers to shoot in tense, rapidly evolving, uncertain circumstances, and those factors put the burden for what happens right where it belongs-squarely on the suspect’s behavior.

“If a subject does the wrong things at the wrong time, a reasonable officer is likely to pull the trigger, believing his own life to be in peril.”

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