L14 - Eyewitness Memory

Question 1

Discuss differences between physical and eyewitness evidence

Answer 1

Physical evidence
 It is often circumstantial evidence (they can say someone has been there but they may not have necessarily have been related to the crime)
 Protocols for collecting, preserving and interpreting physical evidence are dictated largely by forensic scientists
 Protocols have a scientific foundation, grounded in what experts suggest are optimal ways to avoid contamination
 Physical evidence is often ‘circumstantial’

Eyewitness evidence
 Typically collected by non-specialists in human memory
 Protocols for collecting preserving and interpreting eyewitness evidence has not incorporated scientific psychological research to the extent that it could
 Often directly links suspect to crime; therefore goes beyond circumstantial evidence

Question 2

Define the misinformation effect

Answer 2

Exposure to incorrect information about an event after it has occurred often causes people to incorporate this misinformation into their memories

Question 3

Describe the 3 ways a witness might encounter post-event misinformation

Include examples for each one

Answer 3

1. Leading questions about the event
   o Example: McMartin Preschool
    1980s
    Seven teachers accused of kidnapping kids
    Laid over 200 charges over these 7 teachers
    Only 2 end up being trialed
    However the interviews with the kids were very misleading
    They had reported helicopters taking the kids to an abandoned farm (however, surely people would have noticed helicopters leaving the preschool)
   o Research: Loftus & Palmer 1974
    Participants shown a film of a traffic accident
    Participants asked “how fast were the cars going when they smashed into each other” gave higher speed estimates than those asked, “how fast were the cars going when they hit each other”
    A week later, participants in the smashed condition were more than twice as likely to recall broken glass when in fact there was none
2. Hearing about the event from the media
   o Example: Washington Sniper
    2002, a sniper in Washington
    Randomly showing up all over town, gunning people down
    Some witnesses had reported they had seen a White van fleeing the scene
    So they told the media to watch out for this van
    But they’re a lot of white vans that are perfectly fine
    When they found the people they were actually in a blue car, so the white van was incorrect information
   o Research: Wright & Stroud 1998
    Showed participants pictures of a shoplifting incident
    Participants then read a brief summary of the crime, which included some incorrect details
    Results indicated that participants incorporated the incorrect details from the summary into their memories
3. Hearing about the event from other witnesses
   o Example:
    Co-witnesses: two or more people who witness the same event
    Case:
   • Peter Hain
   o Seem him around the scene and accused him of bank robbery, just because multiple people have gotten together and said they saw him around the scene at this time
   o One person mis-remembering the information can influence everyone else memory
   o Eyewitness survey:
    86% of witness report discussing the event with a co-witness
    The most frequent reason: “providing information”
    More witnesses reported that they had been encouraged by the police to discuss the event with co-witnesses than discouraged

Question 4

2 theories about the misinformation effect

Answer 4

Alternation hypothesis:
o Original information does not exist because:
 Vacant slot explanation (you didn’t even pay attention, so you encoded anything much easier because you have a vacant slot)
• Misinformation is accepted because individual failed to encode original information
 Overwriting explanation
• Post-event information overwrites the original memory
 Blend explanation
• Participants encode misinformation in same cognitive structure as the original information which results in a blend (e.g. colours, numbers)
• To stop this from happening you need to prevent the misinformation from occurring

Co-existence hypothesis:
o Both memory for original event and misinformation are stored and each memory is capable of being recovered. Original memory is not replaced, but is less accessible than the subsequent misleading information, perhaps owing:
 Recency effect
• You remember the more recent information more than other information
 Retroactive interference
• When we learn something new it makes us forget what we originally learned

Question 5

What are factors that increase susceptibility?

Answer 5

Factors that increase susceptibility to the misinformation effect:
o Age (young and old)
o Hypnosis
o Suggestibility (Guddjonsson Suggestibility Scale)
o Misinformation is repeated
o Misinformation is peripheral

Question 6

How can people be less susceptible to misinformation?

Answer 6

People will be less susceptible to misinformation if:
o The misinformation blatantly contradicts what was originally witnessed
o Source of the misinformation in not credible
o They are forewarned that they may encounter misinformation, however, warning them that they have encountered information a week after the fact, doesn’t help combat the misinformation effect
o They first make a public statement about what they witnessed
o There is less time between witnessing the event and the presentation of misinformation

Question 7

How can eyewitness memory be improved?

Answer 7

• To preserve memory integrity, statements should be obtained as soon as is practicable following an incident (before it is forgotten)
• An immediate recall tool that elicits a comprehensive statement from eyewitnesses may increase the quality and quantity of accurate information that they provide
• The Self-Administered Interview is an example of such an immediate recall tool
• It is a paper-and-pencil self-explanatory response booklet for witnesses to record their memories at the crime scene
• Completing the SAI soon after witnessing a crime:
  o Minimised memory decay
  o Maintains accuracy
  o Protects against memory contamination from PEI sources
• BUT:
  o The paper format means that the tool is very generic and inflexible
  o The tool is only appropriate for one-off events, and not incidents that are repeated or ongoing (e.g. not good for work-place bullying etc.)
  o The tool does not accommodate the needs of different types of witnesses (e.g. lower literacy)

iWitnessed

• Can be used for any type of event ranging from traffic accident to terrorism
• Uses guided recall procedure that has been designed to help you remember details of an event
• You can enter the information as text, images, audio
• Each report can be ‘stamped’ with the date, time and GPS location