Perceptual and Memory Distortion
During Officer-Involved Shootings
FBI Law Enforcement Bulletin
Oct. 2002, p.18 - Research Forum
(IACP Net document No. 564080)
Article in PDF format at
www.fbi.gov/publications/leb/2002/oct02leb.pdf
By Alexis Artwohl, Ph.D.
Artwohl@cs.com
www.alexisartwohl.com
Background
Previous Research
Present Research
Past and Present Survey Results
Implications for Investigators
Implications for Training
Conclusion
"If it hadn't been for the recoil, I wouldn't have known
my gun was working. Not only didn't I hear the shots but afterward my ears
weren't even ringing."
"I saw the suspect suddenly point his gun at my partner.
As I shot him, I saw
my partner go down in a spray of blood. I ran over to help my partner, and he
was standing there unharmed. The suspect never even got off a shot."
"When I got home after the shooting, my wife told me that
I had called her on my cell phone during the pursuit of the violent suspect just
prior to the shooting. I have no memory of making that phone call."
"I told the SWAT team that the suspect was firing at me from down a long dark
hallway about 40 feet long. When I went back to the scene the next day, I was
shocked to discover that he had actually been only about 5 feet in front of me
in an open room. There was no dark hallway."
"During a violent shoot-out I looked over, drawn to the
sudden mayhem, and was puzzled to see beer cans slowly floating through the air
past my face. What was even more puzzling was that they had the word Federal
printed on the bottom. They turned out to be the shell casings ejected by the
officer who was firing next to me."
These representative samples, taken from actual officer-involved shootings,
exemplify the quirky nature of perception and memory. Law enforcement officers
fully realize that their superiors, legal authorities, and the public they serve
will hold them completely accountable for their every action during an
officer-involved shooting. These same individuals also will scrutinize the
accuracy and truthfulness of statements made by officers taking part in such
incidents. Therefore, it becomes important to understand that expecting officers
to have perfect recall of any event is not realistic. Indeed, the body of
research on perception and memory supports the fact that people rarely are
capable of total and perfect recall of events.
Although the underlying physical processes of perception and memory continue as
a matter of research and debate, empirical observation of human behavior can
shed some light on the behavioral consequences of these processes. To this end,
the author focused her research on the self-reported perceptual and memory
distortions experienced by officers involved in shootings.1
Background
Germane to this topic is how trauma and other highly emotional experiences can
impact perception and memory. A noted researcher in the area of stress and fear
conducted a comprehensive review of this topic.2 He came to the conclusion that
people have two distinctly different modes of processing information. One, the
rational-thinking mode, happens during low emotional arousal states, whereas the
second, the experiential-thinking mode, occurs during states of high stress and
emotional arousal, such as would occur during an officer-involved shooting.
He pointed out that when people are not under high levels of stress, they
have the ability to calmly engage in the conscious, deliberative, and
analytical cognitive processing that characterizes rational thinking.
However, when a perceived emergency requires quick action, they cannot afford
this luxury. Instead, their cognitive processing system automatically
switches over to experiential thinking. He stated that "people are angry,
sad, or frightened not as a direct result of what objectively occurs but
because of how they interpret what happens. The automatic, preconscious
construals that are the effective instigators of such emotions are made so
automatically and rapidly as to preclude the deliberative, sequential,
analytical thinking that is characteristic of the rational system."3
He delineated the differences in rational and experiential thinking,
including the concept that experiential thinking represents a system that
"automatically, rapidly, effortlessly, and efficiently processes
information,"4 an obvious advantage in a life-threatening situation demanding an
immediate response. Along with facilitating automatic, rapid responses, he
pointed out that experiential thinking is more likely than rational to have such
characteristics as --
* fragmented memory instead of an integrated narrative;
* based on past experiences instead of a conscious appraisal of events;
* intuitive and holistic instead of analytic and logical;
* oriented toward immediate action instead of reflection and delayed action;
* highly efficient and rapid cognitive processing instead of slow,
deliberative thinking;
* "seized by emotions" instead of "in control of our thoughts"; or
* "experiencing is believing" instead of requiring justification via logic
and evidence.
He continued with, "In most situations, the automatic processing of the
experiential system is dominant over the rational system because it is less
effortful and more efficient and, accordingly, is the default option."5 He
noted that people frequently engage in experiential thinking during everyday
events simply because it is more efficient, but "emotional arousal and relevant
experience are considered to shift the balance of influence in the direction of
the experiential system."6 This clearly applies to officers
involved in shootings and other high-stress situations.
Previous Research
To understand this connection more thoroughly, the author reviewed previous
research relative to officer-involved shootings. In the process, she
concentrated on three main studies.
In 1986, two researchers were among the first to publish data specific to
officer-involved shootings.7 In their study of 86 officers involved in
shootings, they found that 67 percent of the officers saw the incident in
slow motion, while 15 percent observed it as faster than normal. Fifty-one
percent heard sounds during the event in a diminished manner, whereas 18
percent of the officers said that the sounds were intensified. Thirty-seven
percent had tunnel vision, while 18 percent experienced greater visual
detail.
In 1998, two other researchers studied a variety of reactions in 348 officers
involved in shootings.8 They administered their surveys within 3 to 5 days after
the incident, just prior to each officer's participation in a mandatory
debriefing. They found that 41 percent of the officers thought that time slowed
down, while 20 percent perceived that it sped up. Fifty-one percent said that
sounds seemed quieter, whereas 23 percent reported sounds as being louder.
Forty-five percent of the officers had tunnel vision, while 41 percent
experienced an increased attention to detail. In addition, 22 percent of the
officers reported memory loss for part of the incident.
A recent researcher did a comprehensive survey of officer-involved shootings
that consisted of detailed interviews with 80 municipal and county law
enforcement officers who reported on 113 separate cases where they shot citizens
during their careers in law enforcement.9 While his report contained a wealth of
information, it also set out specific data relative to perceptual and memory
distortions. He found that 56 percent of the officers saw the incident in slow
motion, while 23 percent thought that it happened quicker
than normal. Eighty-two percent reported that sounds diminished, whereas 20
percent thought sounds intensified. Fifty-six percent experienced heightened
visual detail, while 51 percent had tunnel vision. In addition, 13 percent of
the officers reported other types of distortion during the event.
Present Research
From 1994 to 1999, the author supplied a written survey to 157 officers
involved in shootings from multiple agencies. Although approximately
two-thirds of the officers received the survey during their individual
mandatory debriefing within 1 week after the shooting, the author told them not
to fill out the survey until they had attended a group debriefing (which
typically occurs 2 to 4 weeks after the incident, allowing time for agencies to
complete their investigations). The author did this because she discovered, in
the course of conducting numerous group debriefings, that many officers do not
fully realize the extent of their own memory and perceptual gaps and distortions
until confronted with evidence to the contrary. During a group debriefing, as
officers tell their versions of what happened, the complete picture begins to
emerge. Participating officers enjoy the benefit of finding out what really
happened overall and how their own version might differ. Even for officers who
were the only officer present, their later perusal of investigation reports,
including physical evidence and eyewitness statements, can educate them as to
the lack of completeness and total accuracy of their memories of the event.
By contrast, the author collected the remaining one-third of the surveys from
mental health or law enforcement professionals who gave the surveys to officers
who they knew had been involved in shootings. With these surveys, the length of
time that had passed since the shooting occurred varied more than those
collected after group debriefings.
In addition, the sample did not represent a "clinical" population; these
officers were not seeking treatment for post-traumatic stress disorder
(PTSD), although some may have been experiencing a certain degree of PTSD. The
majority of the officers who completed the surveys collected by the author were
doing well emotionally by the time their group debriefing occurred. The officers
voluntarily filled out the surveys, and the great majority of the officers
returned them to the author.
Overall, the author's research revealed that 62 percent of the officers
viewed the incident in slow motion, while 17 percent said that time appeared to
speed up. Eighty-four percent of the officers noted that sounds seemed
diminished, whereas 16 percent thought that sounds were intensified.
Seventy-nine percent had tunnel vision, while 71 percent experienced heightened
visual clarity. In addition, 74 percent of the officers stated that they
responded on "automatic pilot," with little or no conscious thought. Fifty-two
percent reported memory loss for part of the event, and 46 percent noted memory
loss for some of their own behavior. Thirty-nine percent recalled experiencing
dissociation (i.e., the sense of detachment or unreality); 26 percent had
intrusive distracting thoughts; 21 percent noted memory distortion (i.e., saw,
heard, or experienced something that did not really happen or it happened very
differently than they remembered); and 7 percent reported having temporary
paralysis.
Discussion
Past and Present Survey Results
Diminished sound refers to the inability to hear very loud sounds that a
person ordinarily obviously would hear, such as gunshots. It ranges from not
hearing these sounds at all to hearing them in an odd muffled, distant
manner. This may contribute to the findings of previous researchers, as well as
the author, indicating that officers often do not know exactly how many rounds
they fired, especially as the number of shots increases.
Tunnel vision denotes the loss of peripheral vision. This, combined with
heightened visual clarity, can result in the odd combination of officers
seeing with unusual detail some stimuli within their narrowed field of
vision, but remaining visually oblivious to the surroundings that they
ordinarily would see with their peripheral vision.
Although 7 percent of the officers reported temporary paralysis, such a
reaction is unlikely to represent "freezing" to the point of dysfunction
during the event. In cases where the author debriefed officers who were angry at
themselves for "freezing," she found that, in fact, this was simply the normal
"action-reaction" gap that occurs because the officers can shoot only after the
suspect has engaged in behavior that represents a threat.10
Although this gap occurs in a very brief span of time, because of the common
perceptual distortion of slow-motion time, it can seem to the officers as if
they stood there forever after perceiving the threat and before responding.
While it remains possible that some of the respondents did, in fact, totally
"freeze," it is unlikely that as many as 7 percent did. Perhaps, none did.
Intrusive distracting thoughts are those not immediately relevant to the
tactical situation, often including thoughts about loved ones or other
personal matters. In addition, memory gaps and perceptual distortions can
result in "flash-bulb" memories, where the individual has a series of vivid
images burned into memory, with the rest of the event somewhat fuzzy, a bit out
or order, or even missing.
The author found one notable aspect about all of the studies. None quantified
other perceptual distortions that can occur, such as distance distortion, color
distortion, face recognition distortion, or lighting distortions.
Overall, although some of the studies found similar results on various items,
inconsistencies also occurred in several items from study to study.
Regardless of the methodological differences that might have contributed to
these deviations, the most important finding remained the same for all. That is,
independent studies using different methodologies found that memory and
perceptual distortions, in fact, did occur to some degree in officer-involved
shootings. Therefore, those who analyze the actions and statements of officers
involved in shootings must take these findings into account. Two researchers
stated this clearly after finding that 22 percent of officers in their survey
experienced memory loss.
While other studies have reported even higher numbers,
22 percent remains a highly significant amount given that the officers will be
expected to testify regarding their actions sometime in the future. What appears
to be a relatively common perceptual disturbance following involvement in a
critical incident has the potential of opening up the officers to accusations of
either outright lying or withholding the truth. This is particularly relevant
should subsequent interviews result in additional observations or
clarifications, as is often the case.11
Implications for Investigators
These researchers accurately pointed out that memory is not a flawless
"videotape" that can play back exactly the same way each time a person tries to
remember a past event. Rather, memory is a creative and not entirely understood
process. If an officer's recollection of an event is not a totally accurate
representation of reality, it does not necessarily mean that the officer is
lying or trying to engage in a cover-up. Likewise, it is normal
for memories to change somewhat over time, and the changed or new memories may
or may not represent reality more accurately. The same concept applies to other
eyewitnesses and the suspects as well. No one should accuse an individual of
lying simply due to inaccurate, inconsistent, or missing memories. While some
individuals will choose to be untruthful, investigators should reserve this
accusation for those cases where additional evidence exists to indicate that the
person deliberately lied.
The author found that 21 percent of the officers "saw, heard, or experienced
something during the event that I later found out had not really happened or
happened very differently than how I remembered it." All participants in an
event, including the suspect, eyewitnesses, and officers, have the potential to
see, hear, feel, or experience things that did not actually happen. A wide
variety of factors, including perceptual distortions, biases, beliefs,
expectations, and prior experiences, influence people's perceptions. An
interesting aspect to these memory distortions that the author repeatedly has
observed is that they can "feel" more real to the witness than what actually
happened. This remains consistent with the observation that experiential
thinking is "self-evidently valid: 'seeing is believing,'" as opposed to
rational thinking, which "requires justification via logic and evidence."12 When
confronted with a videotape that conclusively proved that he saw things that did
not happen, a veteran SWAT officer told the author, "Doc, I now intellectually
know that what I thought I saw didn't really happen, but it still feels more
real to me than what I saw on the tape." Some witnesses sincerely and vehemently
will insist that their perceptions and memories are accurate when, in fact, they
may not be accurate at all.
The differences between rational and experiential modes of thinking also have
implications in the postshooting aftermath. Clearly, officers need to be held
accountable for all of their on-duty behavior, especially if they must use
deadly force. However, those who conduct postshooting analyses should keep two
things in mind. First, while officers usually have only seconds (or less) to
decide about using force, all of those doing postshooting analyses will have
hours, weeks, months, or even years to contemplate all of the evidence and
decide what the officers really should have done. Although postincident analysis
can prove very helpful as a learning exercise, it was not an option available to
the involved officers at the time of the shooting. Second, research indicates
that officers will be in the experiential-thinking mode because it is the
default option, especially in emotionally laden situations. On the other hand,
all of those engaged in postshooting analyses have the ability to analyze the
officers' behaviors in rational-mode thinking, a different cognitive process
altogether and a luxury that the officers did not have during the shootings.
This does not suggest that officers be given carte blanche to behave in any way
they want during a high-stress situation. It does imply, however, that the law
enforcement profession must remain rigorous in its training, realistic in its
expectations, and cognizant of the demands of emergency situations.
Another research review found that "traumatic situations will inevitably
result in memory impairment."13 These researchers pointed out, and the author
agrees, that officers may make more thorough and accurate statements if they
wait at least 24 hours, during which time they should get some sleep, before
participating in their formal interview with investigators. Research evidence
suggests that REM (rapid eye movement) sleep, in particular, helps integrate
memories and facilitate learning and memory retrieval. Some officers might
appear unusually calm shortly after an incident and may prefer to give an
immediate full statement. Often, however, it is best for officers to sleep first
and give their statements later. This does not preclude their providing enough
brief information during an immediate on-scene "walk-through" to get the
investigation started. But, investigators must conduct these initial sessions in
a sensitive manner that does not compromise the officers' legal rights.
Given that perceptual and memory distortions are an integral part of
traumatic events, investigators may find research on the cognitive interview
technique helpful.14 The developers of this method found that how investigators
interview individuals can significantly impact the ability of the witnesses to
remember and report the details of an event. Their research indicated the
cognitive interview as the most effective technique for facilitating memory
retrieval with cooperative witnesses. Using proper interview techniques is
particularly important for high-stress situations because during experiential
thinking, the individual is more likely to be dissociative and "encodes reality
in concrete images, metaphors, and narratives," whereas, in rational thinking,
the individual is more logical and "encodes reality in abstract symbols, words,
and numbers."15 This means that the survivors of traumatic experiences will find
it challenging to translate the dissociated concrete images and metaphors they
experienced during the high-stress event into the sequential, verbal, abstract,
and logical narrative required by an investigative interview and courtroom
testimony. Skilled investigators can help witnesses with this difficult task.
Implications for Training
Seventy-four percent of the officers that the author surveyed reported, "I
responded automatically to the perceived threat giving little or no conscious
thought to my actions." This finding coincides with the experiential-thinking
mode, described as an "automatic, intuitive mode of information processing that
operates by different rules from that of the rational mode" that "occurs
automatically and effortlessly outside of awareness because that is its natural
mode of operation, a mode that is far more efficient than conscious,
deliberative thinking."16 This has profound implications for training because
experiential thinking is based on past experiences. Therefore, under sudden,
life-threatening stress, individuals likely will exhibit behavior based on past
experiences that they automatically will produce without conscious thought. This
means not only training officers in appropriate tactics but also providing
sufficient repetition under stress so that the new behaviors automatically will
take precedent over any previously learned, potentially inappropriate, behaviors
that they possessed before becoming an officer.17
Another implication of the author's study, as well as other research, is that
it supports the concept of reality-based training that all tactically minded
officers and trainers know represents the foundation for reliable performance in
high-stress situations. "Information obtained from textbooks and lectures is of
a different quality from information acquired from experience. Experientially
derived knowledge often is more compelling and more likely to influence behavior
than is abstract knowledge."18
This is especially critical in sudden, high-stress situations requiring
instant physical performance. Abstract knowledge obtained in lectures and
books can be very useful in rational-thinking mode situations, such as
formulating policies and analyzing situations. However, when officers face
sudden, life-threatening incidents, their reality-based training experiences
most likely surface.
Reality-based instruction that subjects the participants to high levels of
stress during training also will help officers develop coping mechanisms to
compensate for perceptual and memory distortions. For instance, to compensate
for tunnel vision, many officers have learned to practice visually scanning the
tactical environment during high-stress situations, such as pursuits and
high-risk entries. Training under stress also will help officers learn to
control their arousal level. As their physiological agitation escalates, so
might their susceptibility to perceptual and memory distortions. Thus, learning
to control arousal level can help reduce distortions. Therefore, officers should
receive training in and regularly practice ways to control arousal levels in
high-stress situations. One process, the combat breathing technique, has proven
highly effective in this area.19
Officers and their family members also should receive training on what
reactions they can expect during and after high-stress situations, such as
shootings. Providing officers and their family members with information on what
to expect can help them cope better with highly stressful events.20
Finally, those who analyze or participate in the aftermath of
officer-involved shootings should receive training as well. Such individuals
could include attorneys, association representatives, peers, juries,
journalists, command staff and supervisors, mental health professionals,
employee assistance personnel, worker compensation employees, and any others who
have a vested interest in these events. This will better enable them to make
informed, reasonable judgments about the officers' behaviors and advocate for
the type of training and postincident care that the officers will need to best
serve and protect their communities.
Conclusion
The observations of the officers at the beginning of this article effectively
portray how perception and memory can influence an individual's understanding of
a particular incident. One officer did not hear the sound of his gun
discharging. Another did not remember calling his wife just prior to being
involved in a shooting. Three others observed things happening in ways that did
not actually occur. All of the officers were involved in the highly stressful
and emotionally laden process of using deadly force and, therefore, subject to
later scrutiny by their agencies and the citizens they serve for their actions.
Although highly trained in accurately describing events and uncovering facts
pertinent to criminal investigations, law enforcement officers face the same
difficulties that all people do when trying to recall what happened in
high-stress situations. Research has revealed that people rarely can remember
such events with total accuracy. The author's study, along with other research
she examined, demonstrated that this finding holds true for officers involved in
shootings. With this in mind, the law enforcement profession must realize the
implications this has for officers and those who analyze their actions. Because
critical incidents demand split-second decisions, officers must receive the best
training that will help them react appropriately in high-stress situations.
Likewise, those who analyze these events must understand the demands placed on
officers during such incidents and maintain realistic expectations concerning
what officers perceived during the events and what they can recall accurately
afterwards. In the end, recognizing the perceptual and memory distortions that
officers can have during a shooting can go a long way toward helping officers
deal with such difficult situations and, perhaps, reduce their occurrence.
Endnotes
1. Officers can contact Dr. Artwohl, coauthor of Deadly Force Encounters:
What Cops Need to Know to Mentally and Physically Prepare for and Win a
Gunfight (Boulder, CO: Paladin Press, 1997), at
artwohl@cs.com
 or access her
Web site at
http://www.alexisartwohl.com
2. Seymour Epstein, The Integration of the Cognitive and Psychodynamic
Unconscious, American Psychologist
49 (1994): 709-723.
3 Ibid.
4. Ibid.
5. Ibid.
6. Ibid.
7. R.M. Solomon and J.M. Horn, “Post- Shooting Traumatic Reactions: A Pilot
Study, in Psychological Services for Law Enforcement, eds. J.T. Reese and
H.A. Goldstein (Washington, DC: U.S. Government Printing Office, 1986).
8. A.L. Hoenig and J.E. Roland, Shots Fired: Officer Involved, Police Chief
, October 1998.
9. David Klinger, U.S. Department of Justice, National Institute of Justice,
Police Responses to Officer-Involved Shootings, NCJ 192285 (Washington, DC,
October 2001).
10. Bill Lewinski, “Why Is the Suspect Shot in the Back?” The Police
Marksman, November/December 2000.
11. Supra note 8.
12. Supra note 2.
13. D. Grossman and B.K. Siddle, Critical Incident Amnesia: The Physiological
Basis and Implications of Memory Loss During Extreme Survival Stress
Situations (Millstadt, IL: PPCT Management Systems,
Inc., 1998).
14. R.P. Fisher and R.E. Geiselman, Memory Enhancing Techniques for
Investigative Interviewing (Springfield, IL: Charles C. Thomas, 1992).
15. Supra note 2.
16. Supra note 2.
17. Charles Humes, The Flashlight Dilemma, Tactical Edge, 1992.
18. Supra note 2.
19. Charles Humes, “Lowering Pursuit Stress,” Police, June 2001.
20. D. Meichenbaum, Stress Inoculation Training (Boston, MA: Allyn & Bacon,
1985).
.the law enforcement profession must remain rigorous in its training,
realistic in its expectations, and cognizant of the demands of emergency
situations.
