JSB174 Lecture Notes - Lecture 9: Eyewitness Testimony, Penrod, Reasonable Doubt
JSB174 Forensic Psychology and the Law
Week 9 Lecture Notes Part 3
Inadmissible Evidence
• ‘Strike that from the record’, ‘I object’, jurors do not ignore extra-legal or
inadmissible evidence
• Sometimes the back-fire effect occurs, the judge’s instruction to disregard the
information actually makes it more memorable
Juror Competence
• As case complexity increased, jurors less sure their verdict reflected a proper
understanding of instructions (Heuer and Penrod, 1995)
• Serious difficult comprehending difference between legal concepts (Severance and
Loftus, 1982)
o Reasonable doubt
o Criminal intent
o Use of prior offence history
• 224 people called for jury duty, research indicated they understood less than 50% of
instructions
• Comprehending evidence:
o Jurors are conscientious about their task, but this fades away during the trial
(McCabe and Purves, 1974; Stephenson, 1992)
• Visher (1987) found four types of evidence that significantly influenced jurors:
o Physical evidence
o Eyewitness testimony
o Discrediting testimony and evidence
o Extra-legal factors of social class, education and personality
Juror Characteristics
• Convictions more likely with:
o Older jurors
o Higher educational standard
o Previous jury experience
o Female jurors
▪ But only in rape cases, or child sexual abuse cases
• Race of jury does not matter
The Cognitive Story Model
• Jurors actively construct explanations for the evidence and use this to guide their
verdict
• They interpret and elaborate on evidence to create a cohesive story
• Jurors bring their own individual differences – attitudes, beliefs, knowledge – in
contributing to the story
