Eyewitness Identification and Testimony
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Chapter7PPT1.pptxEyewitness Identification and Testimony
Chapter 7
In This Chapter
Eyewitness Testimony and the Legal System
The Construction and Reconstruction of Eyewitness Memories
Using Research Findings to Improve Eyewitness Accuracy
Techniques for Refreshing the Memories of Witnesses
Eyewitness Identification
Eyewitnesses rely on memory.
Encoding (gathering)
Storage (holding)
Retrieval (accessing)
Errors can occur at each stage.
Imperfect incoding
Memory trace deterioration
Retrieval distortion
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Eyewitness Testimony and the Legal System
Involves most compelling evidence in court
Is most persuasive to a jury
Leads to more wrongful convictions than any other evidence
Four Major Causes of Wrongful Convictions
Figure 7.1
The incidence of other causes—especially law-enforcement misconduct,
prosecutorial misconduct, and bad defense lawyering—are difficult
to calculate. Percentages add up to more than 100% because many
cases involve more than one cause. (Data source: www.innocence
project.com)
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Eyewitness Testimony and the Legal System
Manson Criteria is used to evaluate testimony accuracy.
Influenced by two key cases
Neil v. Biggers (1972)
Manson v. Braithwaite (1977)
Eyewitness Testimony and the Legal System
Factors in Mason Criteria
Opportunity
Accuracy of description
Level of attention
Degree of certainty
Time lap between crime and identification
Eyewitness Testimony and the Legal System
Difficulty in applying Manson Criteria with certainty
Evaluation of witness attention and view time of perpetrator limited
Witness overestimation of view time
Effects of time between witnessing crime and criminal identification
Biased questioning and lineup procedures
Undue juror faith in reliability of eyewitness testimony
Eyewitness Testimony and the Legal System
Legal system attempts to expose eyewitness bias
Determining witness ability to observe
Voir dire
Cross-examination
Jury deliberation
LEGAL UPDATE
Post-Manson court decisions on eyewitness identification
Perry v. New Hampshire (2012) (U.S. Supreme Court)
Issue of eyewitness evidence revisited but Manson criteria not updated
Fallibility of eyewitness identifications noted
State v. Henderson (2011) (NJ Supreme Court)
Manson rule does not provide sufficient reliability measure, does not deter, and overstates jury’s ability to evaluate eyewitness testimony
State v. Lawson (2012) (OR Supreme Court)
Prosecution must prove identification was based on permissible basis; role for eyewitness testimony established
Construction and Reconstruction of Eyewitness Memory
Cross-racial identification
Cross-race effect (own-race bias) present from infancy to adulthood; not large bias effect, but consequential for legal system
Stress and weapons focus
Stress effects encoding
Weapons focus effect (witness focus on weapon, not assailant)
Cross-racial identification
Improves with contact with members of other groups
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Figure 7.3
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Construction and Reconstruction of Eyewitness Memory
Unconscious transference
Face seen in one context transferred to another
Suggestive or leading comments
Eyewitness recall shaped by wording of questions
Inhibition of details through retrieval inhibition
Preexisting expectations
Interaction of beliefs about sequence of actions in a case (scripts) with prior knowledge
Witness Confidence
Confident eyewitness
Persuades jurors/judge
Confidence
Highly correlated with persuasiveness
Weakly correlated with accuracy as witness investment in identification correctness increases over time
Confidence manipulation
Postidentification feedback effect strengthened through cognitive dissonance
Witness Confidence
Child eyewitnesses
Are about as accurate as adults in culprit-present or culprit-absent lineup
Are less accurate than adults in culprit-absent or target-absent lineup
Provide less information
Are more suggestible
Research to Improve Eyewitness Testimony
Estimator variables
Factors outside legal system control
System variables
Factors under legal system control
American Psychology-Law Society (APLS) rules used to create police and investigator guidelines
Administration of lineups or photo spreads
Witnesslineup viewing instructions
Composition of lineup
Eyewitness confidence information
Research to Improve Eyewitness Testimony
Guidelines influenced by more recent research
Blind lineup administrators
Bias-reducing eyewitness instructions
Unbiased lineup
Confidence ratings
Video recording
Sequential lineups
Expert testimony
Research to Improve Eyewitness Testimony
Blind lineup: Reduces unintentional communication; blind lineup administrator
Bias-reducing instructions: Forces witnesses to rely on own memory
Unbiased lineup: Requires actual suspect should not stand out from “fillers”
Confidence ratings: Requires confidence statement at time of identification
Research to Improve Eyewitness Testimony
Video recording: Records identification procedures
Sequential lineups: View one person or photograph at a time; reduce relative judgment
Expert testimony: Provides psychologist summary on research related to eyewitness testimony
HOT TOPICS
Translating science into practice
Difficulties
Identification of threshold for policy recommendation
Resistance to reform among responsible reformers
Contingent nature of some research findings
So…does the science of eyewitness evidence substantially transform procedures for information gathering from eyewitness to crime?
What do you think?
Refreshing Memories of Eyewitnesses
Hypnosis
Involves relaxed state, more receptive to suggestion
May facilitate hypnotic hypernesia
Does not increase accuracy; courts skeptical
Cognitive Interview
Involves procedure to relax witness
Reinstates context surrounding crime
Is difficult for police to adopt this method
