Transcript 20021002-PSYCH230

Psychology and the Law
Eye Witness Identification
Plan for Today
• Memory Construction
• Eye witness identification
Memory Construction
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It is surprisingly easy to distort and/or create
memories
Memory is strongly influenced by our views,
attitudes and beliefs at the time of recall
Reform Party MP Jack Ramsay
Elizabeth Loftus’ studies
Schooler (1986) – Psychologists can’t tell the
difference between real and implanted memories
Eye Witness Identification
• Loftus (1979)
• “Did another car pass the red Datsun while
it was stopped at the stop sign?
• It was a yield sign at the intersection the
subject had previously seen.
Loftus & Palmer (1974)
• How fast were the cars going when they
smashed into each other?
• How fast were the cars going when they hit
each other.
• In the first condition subjects “remember”
the cars were going much faster than do
subjects in the second condition.
Our Preconceptions Control our
Interpretations and Memories
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FOLK
CROAK
SOAK
What do we call the white part of an egg?
Priming
• Scary movie
• Subliminal priming
• Stereotype priming
e.g., the elderly
False Identification
• Most common reason for convicting the
innocent.
• In U.S. 77000 cases founded on eyewitness
identification are tried each year.
• The Innocence Project
• Association of the Defense for the
Wrongfully Convicted
Eyewitness Testimony
• Loftus (1979) – Robbery/murder case
- 18% conviction rate jumps to 72% with
addition of eyewitness
- Only falls to 68% with witness discredited
Wells (1981) – even with poor conditions 62%
still believed eyewitness
(1980) – both correct and incorrect
eyewitnesses were believed 80% of the time
Jurors belief of Eyewitnesses
• Wells (1981) – jurors tend to believe witnesses
whose memory for trivial details is poor, but these
are usually the best (most accurate) witnesses
• The more details remembered about the scene, the
less details remembered about the face and victim
• The more confident the witness, often times the
more likely they are to be wrong
Eye Witness Research
• Estimator variables
• e.g. physical and temporal context of the
crime (distance, lighting, duration, weather)
• Age, gender, race, emotional state, witness
eye-sight
• Their impact on the accuracy of an
identification can only be estimated
System Variables
• E.g. procedures used to select members of
line-up, the presentation, instruction given
to witness, conditions in the interview,
interview style
• These are factors over which the police and
justice system have at least some control
Line-ups
• Photo line-ups “head and shoulders”
• Distractors - lineup members other than the
suspect
• Matching to Appearance strategy
• They don’t have to look the similar, they
just have to match the witness’s oral
description
• Unconscious transference
Double Blind Procedure
• Can advertantly or inadvertantly cue the
witness
• e.g. “Take your time” - to tentative
description
• subtle unconscious cues (coughing, voice
inflection)
• reinforcement can raise witness confidence
levels (witness confidence trumps accuracy)
Instructions to the Witness
• “The person you saw commit the crime may
or may not be in the photos you are about to
see.”
• Present the photos sequentially (Lindsay
and Wells 1985)
• relative vs.absolute judgement strategies
Sequential Photo Lineup
• 1. You are going to see a series of photos to determine
whether you can identify the person you saw commit the
robbery last week. Please keep in mind that the person you
saw may or may not be in the photos.
• 2. You will be shown the photos one at a time and you will
not be told how many photos there are. For each photo,
please decide, “Yes that is the person I saw” or “No, that is
not the person I saw.”
• 3. If you say no to a photo you will not be able to return to
it later and if you choose a photo you will not be allowed
to see any remaining photos.
Other Identification Procedures
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Cold mugshot search
Walkthrough procedure
Show up procedure “Oklahoma lineup”
Composite sketch
Identi-Kit and Photo-Fit
Eyewitness Identification
• Confidence is not a reliable indicator of accuracy
• We perceive events selectively and use
imagination to fill in the gaps
• Ample evidence that witnesses often choose the
wrong person from a line up
• Discussion or questioning about events can alter
or add to memory
• Cross racial identification is harder to do than
identification within race