Oct. 2002, p.18 - Research Forum
(IACP Net document
No. 564080)
Perceptual
and Memory Distortion
During Officer-Involved
Shootings
Article in PDF
format at www.fbi.gov/publications/leb/2002/oct02leb.pdf
By Alexis Artwohl, Ph.D.
Past and
Present Survey Results
Implications
for Investigators
"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
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.
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.
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.
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.
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 alexisartwohl@msn.com Ýor access her Web site at http://www.alexisartwohl.com
2. Seymour Epstein, ÑThe Integration
of the Cognitive and Psychodynamic Unconscious,â American Psychologist
49 (1994): 709-723.
3 Ibid.
4. Ibid.
5. Ibid.
6. Ibid.
7. R.M. Solomon and J.M. Horn, ÑPost- Shooting Traumatic Reactions: A Pilot Study,â in Psychological Services for LawEnforcement, eds. J.T. Reese and H.A. Goldstein (Washington, DC: U.S. Government Printing Office, 1986).
8. A.L. Hoenig and J.E. Roland, ÑShots Fired: Officer Involved,â 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, ÑWhy Is the Suspect Shot in the Back?â 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, ÑThe Flashlight Dilemma,â Tactical Edge, 1992.
18. Supra note 2.
19. Charles Humes, ÑLowering Pursuit Stress,â 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.