Eyewitness Testimony Flashcards
Reconstructive memory stages
Perception/Attention
Encoding: gathering information and putting it in a form that can be held in memory (events, situations, etc).
Retention/Storage: how information is stored over time; short term vs. long term
Retrieval: find (or access) what has been stored
Eyewitness Testimony
The memory you have after you witness a crime or an event
Reporting memories = eyewitness evidence
Why is eyewitness testimony important
Police investigations
Arresting/Charging a Suspect
Convicting or exonerating a suspect in court
Hugo Münsterberg
On the witness stand
Type of critical info witnesses can supply
Memory for people:
Criminal descriptions (recall)
Identifications (recognition)
Recognition memory
Memory for events:
Interviews
Recall memory
Criminal Descriptions
Functions:
Provide a basis for the construction of an artist’s sketch
Narrows search of possible suspects
Basis for selection of lineup members
Proper Interview Techniques
Open ended; not suggestive or misleading; individual interviews; enhanced cognitive interview
Research:
Vague (e.g., tall, brunette, male, medium build, wearing a black jacket and jeans)
Adults provide approximately 7 – 10 descriptors on average (Pozzulo & Warren, 2003)
Clothing is the most common descriptor (likely to change)
Most accurate: Hair (Wagstafff, et al., 2003)
Most inaccurate: Height, weight, eye colour
Recent strategy for criminal description
Use of a “standard” person for reference while responding to questions about target
Was the culprit’s hair shorter or longer than mine?
Does not appear to improve the accuracy of descriptors
May aid witnesses when recalling descriptors that often are not remembered, such as the appearance of the eyes, nose, or mouth
Lineup Identification
Function:
To gain proof about the likelihood the suspect is the culprit beyond the information provided in the description.
How are lineups presented
Live Videos (most desired) Photographs (most common) More convenient: -Less time-consuming to construct; -Portable (witness doesn’t have to be at police station). -Suspect doesn’t have right to counsel -Suspect can’t draw attention to him/herself -Decrease anxiety experienced by witness
Show Up Method
Only the suspect is shown to the witness
May be used if:
Death-bed ID
Suspect is apprehended close (time/place) to crime scene
Pro: Absolute judgment likely
Con: Biased witness knows the person the police suspect
Simultaneous Method
The suspect is placed among fillers or foils.
All lineup members are shown at one time
Elicits a relative judgment
Correct 70-75% of the time
Sequential Method
All lineup members are shown individually in a sequence
Witness MUST make a decision BEFORE seeing another member
Witness CANNOT see previously seen photos and does NOT know how many photos they will be shown
Elicits an absolute judgment (Wells et al., 1998)
Correct 65-70% of the time
Standard Instructions when presenting lineups
Person of interest may or may not be in the collection of photos (or live lineup), therefore, you should not feel that someone must be chosen.
He may or may not have the same appearance as at the time he was observed. Keep in mind that appearances and clothing change.
If you recognize someone, provide the person’s number and the basis of your recognition.
Memory is a mixture of:
What actually happened
What a person heard about the event
Feelings about what happened
Any other information used to ‘fill in gaps
** Memory is suggestible
Elizabeth Loftus (Loftus & Pickrell, 1992)
Conducted a study to see if she could implant memories.
Told participants some stories of their past: some were true and one that was made up.
25% incorporated the memory (in full or in part) as real and even elaborated on the details.
cross-race effect (CRE)
Witnesses able to remember faces of their own race more accurately than faces of other races
Social-cognitive models
Same race: configure processing
Different race: feature-based processing
Physiognomic homogeneity (“They all look alike”)
Perceptual-expertise model
we tend to classify facial features of people from our own race their in greater details than other races
Interracial contact
We have more contact with people of our own race
Theory with most support
Weapon Focus Effect
Witness attention on weapon rather than the details of the crime
Arousal/Threat Hypothesis
Focus on arousal;
when emotional arousal increases (i.e., when weapon is present), attentional capacity decreases
Unusual item hypothesis
Weapons are unusual, therefore we focus on them more
Biased Lineups
A lineup that “suggests” who the police suspect is
Filler Bias
Suspect is the only lineup member who matches the description of the culprit
E.g., Suspect has a beard and moustache, whereas foils are all clean-shaven
Clothing Bias
Suspect is the only lineup member wearing similar clothing to that worn by the culprit
Instruction Bias
The police fail to mention that the culprit may not be present;
Instead, police imply that culprit is present and that the witness should ID him/her
How persuasive is eyewitness testimony
Police are more likely to arrest/charge
Judges and juries are more likely to convict
Undue weight placed on witness testimony
People believe it to be highly accurate and reliable (Malpass & Devine, 1981)
Single most important factor in conviction
Leading cause of wrongful conviction
Guides for law enforcement
Rule 1. Blind Lineup Administrators
Should not know who suspect is
Rule 2. Bias-Reducing Instructions to Eyewitnesses
The person in question might not be present and do not feel you must make an ID
The person administering the lineup does not know which person is the suspect
Rule 3. Unbiased Lineups
Suspect should not stand out from fillers as being different based on the previous description or on factors that would draw extra attention
Rule 4. Confidence Ratings
Obtain a clear confidence statement in his or her own words at the time of the ID and prior to any feedback
