Eyewitness Testimony
Eyewitness Testimony
Introduction
Memory Misconceptions
How Memory Works
Links
It is becoming almost commonplace now. To hear
of an inmate being freed after being cleared by DNA tests hardly results in
a second thought by most. The question that this web page will address
is why so many innocent people were convicted of crimes in the first place?
Experts say it's often mistaken eyewitness identity that
puts innocent people in prison, and consequently lets the real criminal go
free. Of the first 40 cases overturned by DNA evidence, 36 of them
involved defendants convicted mainly on eyewitness testimony. According
to experts, eyewitness testimony is the worst evidence one could possibly
have, but at trial it is the strongest evidence one could possibly present.
This is because eyewitness testimony adds direct evidence to a prosecution
that would otherwise be based on circumstantial evidence. This is a
problem that has the whole legal system concerned. How can we avoid
using eyewitness testimony in the first place, and secondly, how can we avoid
making identity recall mistakes? The first part of the question is
more appropriately addressed by legal experts, but the second part will be
addressed here.
The issues surrounding eyewitness testimony generally fall
into two areas: law enforcement procedures and the way memory works.
A major problem, say experts, is when police present lineups to witnesses
and do not tell them that the actual perpetrator may not even be in the lineup.
“People have a natural tendency to approach a lineup situation in such a
way that they make what I've called relative judgment,” says Gary Wells,
an expert in eyewitness testimony and a psychology professor at Iowa State
University. “What they'll do is they'll hone in fairly quickly on the person
who looks most like the perpetrator relative to the others.” But if
the perpetrator isn't there, the person in the group who looks most like
him or her is likely to be deemed the culprit. And if the others selected
to be in the lineup don't look anything like the witness description of the
perpetrator, researchers say the lineup is biased. Wells also argues that
by human nature, police may unknowingly influence the witness’ selection by
trying to assist the witness or by showing the relief or excitement that
comes when the witness chooses their suspect.
Complicating police procedures is the way memory works.
Implicit in the acceptance of eyewitness testimony as solid evidence is the
assumption that the human mind is a precise recorder and storer of events.
Human beings hold fiercely to the belief that our memories are preserved
intact, our thoughts are essentially imperishable, and our impressions are
never really forgotten. In a published survey conducted by Dr. Elizabeth
Loftus and her husband Geoffrey Loftus, a fellow psychology professor, 169
individuals from various parts of the United States were asked to give their
views about how memory works. Of these, 75 had formal graduate training
in psychology, while the remaining 94 did not. The non psychologists
had varied occupations such as: lawyers, secretaries, taxi drivers, physicians,
philosophers, fire investigators, and even an eleven-year-old child participated.
Eighty-four percent of the psychologists and 69 percent of the non psychologists
indicated a belief that all information in long-term memory is there, even
though much of it cannot be retrieved. The most common reason for believing
that was based on personal experience and involved the recovery of an idea
that the person had not thought about for quite some time; a second reason,
commonly given by psychologists, was knowledge of the work of Wilder Penfield,
whose studies of brain stimulation in epileptic patients have been used as
evidence to support the theory that memories are stable and permanent.
Some respondents mentioned hypnosis, psychoanalysis, Pentothal, or even reincarnation
to support their belief in the permanence of memory.
However, in fact, human memory is far from perfect or
permanent, and forgetfulness is a fact of life. One of the most obvious
reasons for "forgetting" is that the information was never stored in memory
in the first place; even the most common, everyday items frequently fail
to find a niche in our memory. Take a U.S. penny, for example.
Most people would insist that they know what a penny looks like and would
have no trouble recognizing one when they saw it. However, in a study
conducted in 1979, fewer than half of the subjects were able to pick the exact
copy of a real penny from fifteen possible designs. Ask yourself; which
way does Lincoln's head face? Do you know without looking? Another
common abject that we look at every day is a telephone. Can you remember
the letters that accompany the numbers of your telephone?
Even if we are careful observers and take in a reasonably
accurate picture of some object or experience, it does not stay intact in
memory. Other forces begin to corrode the original memory. With
the passage of time, with proper medication, or with the introduction of
interfering or contradictory facts, the memory traces change or become transformed,
often without our conscious awareness. We can actually come to believe
in memories of events that never happened.
How does memory work, and why does it fail? Scientists
generally agree that memories are formed when neurons link together to form
new connections, or circuits, actually changing the contact between the cells;
in the process, memories are stored. Long-term memories, which include experiences
that happened just a few minutes ago to information several decades old,
are stored in mental "drawers" somewhere in our brains. No one knows exactly
where, although it has been estimated that in a lifetime, long-term memory
can hold as many as 1 quadrillion (1 million billion) separate bits of information.
The "drawers" holding our memories are obviously extremely
crowded and densely packed. They also constantly being emptied out, scattered
about, and then stuffed back into place. Like curious, playful children searching
through drawers for a blouse or pair of pants, our brains seem to enjoy ransacking
the memory drawers, tossing the facts about, and then stuffing everything
back in, oblivious to order or importance. As new bits and pieces of information
are added into long-term memory, the old memories are removed, replaced,
crumpled up, or shoved into corners. Little details are added, confusing
or extraneous elements are deleted, and a coherent construction of the facts
is gradually created that may bear little resemblance to the original event.
Memories don't just fade, as the old saying would have
us believe; they also grow. What fades is the initial perception, the actual
experience of the events. But every time we recall an event, we must reconstruct
the memory, and with each recollection the memory may be changed--colored
by succeeding events, other people's recollections or suggestions, increased
understanding, or a new context.
Truth and reality, when seen through the filter of our
memories, are not objective facts but subjective, interpretive realities.
We interpret the past, correcting ourselves, adding bits and pieces, deleting
uncomplimentary or disturbing recollections, sweeping, dusting, tidying things
up. Thus our representation of the past takes on a living, shifting reality;
it is not fixed and immutable, not a place way back there that is preserved
in stone, but a living thing that changes shape, expands, shrinks, and expands
again, an amoeba-like creature with powers to make us laugh, and cry, and
clench our fists. Enormous powers; powers even to make us believe in something
that never happened.
Dr. Elizabeth Loftus
-Web page for one of the most influential researchers
in current memory theories.
Online Lectures for Eyewitness Testimony
-A psychological perspective on issues regarding eyewitness testimony.
How Accurate is Eyewitness Testimony
-A research report funded by the Social Sciences and Humanities Research Council
of Canada