Studied by 0 people
Looks like no one added any tags here yet for you.
What is the leading cause of wrongful convictions?
Eyewitness misidentification (63% of cases).
What other factors contribute to wrongful convictions?
Misapplied forensic science (53%), false confessions (28%), informants (19%).
What are the two types of eyewitness memory?
Recall memory: Describing events or people through witness/police statements
Recognition memory: Identifying perpetrators or items involved in crime often in a lineup.
What is the difference between system and estimator variables?
System variables: Occur after the crime and can be controlled by the legal system (e.g., lineup procedures).
Estimator variables: Uncontrollable factors at the crime scene (e.g., lighting, stress).
How does stress impact eyewitness memory?
High stress can increase errors in descriptions.
Traumatic memories may enhance accuracy.
How does age affect eyewitness accuracy?
Children recall less and are highly suggestible, however they can accurately recall.
Elderly have attention, vision, and memory impairments, recall less and make more errors.
How does alcohol affect eyewitness memory?
Short-term: Impairs recall of details but preserves overall accuracy.
Long-term: Reduces accuracy for both details and overall recall.
What is the weapon-focus effect?
Witnesses focus on a weapon, reducing recall of other details. This is due to threat hypothesis and unusualness hypothesis.
What is the cross-race effect?
People have better recall and recognition of individuals from their own race. This often leads to misidentification in legal settings e.g. police lineups. (Ronald Cotton)
How does the number of perpetrators affect memory?
More perpetrators lead to divided attention and reduced recall accuracy.
What is a crime schema?
A mental script for crimes that may cause witnesses to recall inaccurate, script-consistent details.
How does familiarity and expertise impact eyewitness recall?
People recall familiar locations, objects, and individuals more accurately. Justice system experts may encode events more systematically.
What is the innocence project
They use DNA evidence to get innocent people out of jail however only %5 of cases have DNA involved.
What are the key aspects of a witness statement
You can’t be forced to make a statement. Making a false statement is an offence. If you don’t give a statement you can still be called to give evidence in court through a subpeona.
How do witnesses with intellectual disabilities affect crime investigations?
They are often seen as unreliable but high functioning ppl with ID can be accurate but often have shorter responses and increased suggestibility.
What are the witness-related estimator variables
Stress, age, alcohol consumption, intellectual disability, victims vs bystanders, and individual differences.
What are the event-related estimator variables?
Optimality of encoding and retention, weapon-focus effect, cross-race effect, level of violence, number of perpetrators, crime schema, and familiarity/expertise.
How does the level of violence affect eyewitness recall
Higher levels of violence reduce recall accuracy as witnesses may focus on emotional response rather than encoding.
How does optimality of recoding and retention affect eyewitness recall
Shorter exposure duration, longer distances, dark lighting, and longer retention intervals lead to bad recall and more omission/commission errors.
How does being a victim vs. a bystander affect eyewitness recall.
Victims recall more accurately (despite stress) because they are often closer to perpetrators.
How do individual differences moderate witness related estimator variables?
The effects of each estimator variable differ across individuals e.g. people who are high self-monitoring (focused on social presentation) often have better eyewitness memory and recall.
Two causes of misinformation in car crash example
Descriptive wording e.g. smashed (overestimation of speed and smashed glass) vs bumped (more accurate and no glass)
False information/leading questions introduced by trusted source e.g. did the car run through the stop/yield sign
The misinformation effect
Information that eyewitnesses are exposed to after crime but before they provide witness statement can cause misinformation/changes in memory. Can act as a system variable.
What increases susceptibility to misinformation
Discrepancy detection principle: delay between original event and misleading information (time weakens recollection).
Certain psychological states e.g. stress, intoxication, or hypnosis
Warnings against misinformation
Can help people resist memory distortion only when they are given before an interview.
Who is most affected by misinformation
Children, elderly people, people with higher empathy, absorption, self-monitoring, and people prone to memory lapses. Misinformation also affects gorillas, pigeons and rats.
Memory impairment hypothesis
Misinformation alters/erases original memory replacing it with false memory
Retrieval impairment hypothesis
Original memory is intact but misinformation disrupts retrieval and recall. Research is in favour of this hypothesis.
Differences between false and real memories
False memories contain more verbal hedges (“I think I saw”), explanatory reasoning (“I must have seen it bc it makes sense”) and fewer sensory details. Hippocampus plays role in distinguishing real and false memory. Sensory areas have greater activation for true memories.
Research on planting rich false memories
Researchers have been able to implant false autobiographical memories e.g. lost in shopping mall, attacked by an animal or nearly drowned in childhood. Ppl gradual develop detailed and emotional memories of these false events.
Co-witnesses
Can be a form of strong misinformation and a system variable if witnesses are able to share recollection after the crime which can create false memories,
False memories
Remembering events that didn’t happen e.g. through suggestion, leading questions, and association. These memories have long-lasting behavioural and cognitive repercussions.
Repressed memories
A type of false memory were people recall experiences later on in life often of abuse. Linked to the satanic panic and people “uncovering” repressed memories through therapy.
What does misinformation/false memory research show about memory
Memory is very malleable, reconstructive, not a perfect recording, and sometimes unreliable.
Target present lineups
Police suspect in lineup is guilty. Correct decision: choose police suspect from lineup.
Target absent lineups
Police suspect in lineup is innocent. Correct decision: do not choose anyone from lineup
Nine recommendations for police lineup procedures
Pre-lineup interview, evidence-based suspicion, double blind administration, lineup fillers, pre-lineup instructions, immediate confidence statements, video-recording identification process, avoid repeated identifications, and avoid showups.
Pre-lineup interview
Acquire robust witness statement that includes factors that may affect statement reliability. This helps ensure memory is uncontaminated/or to detect contamination, helps prevent reinforcement effect, and provides early account to compare with suspect id.
Evidence-based suspicion
Suspect is only part of lineup if there is documented evidence. This reduces change of placing innocent ppl in lineups (target-absent), ensures lineup contain over one suspect and prevents bias or hunch-based lineups.
Double-blind administration
Lineup administrator should not know who suspect is to prevent unintentional cues from officer, protect integrity of evidence and officers credibility.
Lineup fillers
Should contain at least 5 fillers that closely match suspects description (not police records). This prevents guessing based on who stands up and ensures id. is based on memory not lineup construction.
Pre-lineup instructions
Witnesses told: culprit may not be present, id isn’t required, officer doesn’t know suspect, and only choose if confident. Prevents unintentional pressure to make selection and decreases mistaken id. (especially when told culprit may not be present).
Immediate confidence statements
Witnesses should state confidence before feedback is given to prevent confidence inflation/reinforcement. Initial confidence is a strong predictor of accuracy only if immediately recorded.
Video-recording identification process
Entire lineup should be recorded to provide evidence of proper procedures and a court-admissible record that prevents disputes about officer influence.
Avoid repeated identifications
Avoid showing witness same suspect in multiple id attempts as this prevents familiarity effect (witness recognises from lineup not crime) and reduces false identification.
Avoid show-ups
When only one suspect is presented to witness. Show-ups double risk of mistaken identification as they create assumption of guilt.
Perceptions of eyewitness testimonies that most vs least experts agree
Most: wording of questions, lineup instructions, confidence malleability, & mug-shot induced bias.
Least: repressed memories, memory discrimination, event violence, trained observers and id. speed.
Perceptions of eyewitness testimonies that most vs least judges agree
Most: alcoholic intoxication, question wording, child suggestibility, attitudes, and confidence malleability.
Least: hypnotic accuracy, elderly witness, hypnotic suggestibility, and memory discrimination.
Perceptions of eyewitness testimonies that most vs least jurors agree
Most: alcoholic intoxication, question wording, child suggestibility and attitudes
Least: event violence, trained observers, hypnotic accuracy, elderly witness.
Perceptions of eyewitness testimonies that most vs least law-enforcement agree
Most: question wording, alcoholic intoxication, attitudes, mug-shot induced bias, child suggestibility.
Least: Child accuracy, hypnotic suggestibility, event violence, and memory discrimination.
Role of jury
Must decide whether prosecution has proved the case beyond reasonable doubt. They decide the facts of the case and therefore must stay open minded and listen. They must choose representative (foreperson) to deliver verdict.
Roles in the courtroom
Judge (direct jury on relevant law), barristers (prosecution vs defence), court officer, sheriffs officer and court reporter.
Power of eyewitness
Eyewitness testimony is very persuasive evidence and most jurors believe eyewitness accounts (even if they are inaccurate)
Identification accuracy
Assessed by distance between witness and perpetrator, how long the witness saw the perpetrators, the time between offence and identification and whether the witness knew the perpetrator.
CCTV footage and jurors
Often leads to errors in recognition as unfamiliar face matching is unreliable
Criteria jurors use to evaluate eyewitness testimonies
Confidence (most influential factor): assume confidence = accuracy
Consistency: inconsistent testimony = unreliable witness
Detail: more detail = credibility
These beliefs are often inaccurate
Confidence inflation
Confidence increases because of feedback/questioning (system variable)
Truth bias
Assume others are telling the truth and use own behaviour to infer cause of others behaviour.
Fundamental attribution error
Believe witness confidence is due to memory accuracy and not external influence.
Confidence heuristic
Associate confidence with correctness
Cognitive biases
Once juror forms initial impression they selectively interpret new information to confirm their beliefs
Legal safeguards
Expert testimonies (increases sensitivity or increases overall skepticism), cross-examination, judges instructions and Voir dire (lawyers try to exclude biased judges)
Recommendations for reform
Better jury education, improved expert testimony, and reduced weight given to eyewitness testimony.
Expert witness
Provides expert opinion based on knowledge, skill, training, education, and experience. Must be based on sufficient facts/data and reliable principles/methods
