Transcript Eye Witness Testimony

Eye Witness
Testimony
How Can Evidence Be Made More Reliable?
How Can Evidence Be Made More Reliable?
• Many innocent people
have been put in prison
on the basis of
eyewitness testimony.
How Can Evidence Be Made More Reliable?
Questions asked during a
police interview may
distort an eyewitness’s
memory and thus reduce
its reliability
• Karen Matthews (Shannon’s
mum) was arrested for
abducting her own daughter.
• Although we know that
Karen wasn’t the witness 
see this clip to see the
techniques used to elicit
information from Karen
https://www.youtube.com/w
atch?v=6kdVqpcd2mQ
Fisher (1987) found….
• witnesses were frequently bombarded with a series of brief, direct and close-ended
questions aimed to elicit facts – they studied real life interviews by detective
officers in Florida over 4 month period.
• However, the sequencing of these questions often seemed to be out of sync with
the witnesses’ own mental representation of the event.
• Witnesses were often interrupted and not allowed to talk freely about their
experiences.
As they were frequently interrupted….
….this made it hard for the witness to concentrate fully on the process of retrieval
and thus reduced recall
How Can Evidence Be Made More Reliable?
The Home office has now
issued clear guidance based
on psychological research
on police interviews
Interviews should move
from free recall to general
open-ended questions,
concluding with more
specific questions.
How Can Evidence Be Made More Reliable?
Geiselman (1985) argues that interviews should take
into account the following features of human memory:
1. Memory traces are complex containing different
kinds of information.
2. The effectiveness of a retrieval cue depends on the
extent that the information it contains overlaps with
information stored in the memory trace
3. Various retrieval cues may permit access to any
given memory trace. Re-enactments of crimes are a
means of providing cues to retrieve memories.
Cognitive Interviews (Geiselman et al
1985)
Report EVERYTHING
1. The eyewitness then simply reports
everything they can think of relating to the
incident, even if the information is fragmented.
Reinstate the Context
2. the eyewitness tries to recreate mentally the
context that existed at the time of the crime
including the environment and their state of
mind/mood.
Recall in reverse order
3. Report the episode in several different
temporal orders moving backwards and
forwards in time
Different Perspectives
4. The eyewitness is
encouraged to report
the details in various
orders and from
different perspectives
Remember….
• These techniques all designed
to enhance retrieval of the
original memory
• Although this kind of detail
might seem trivial and poorly
related to the actual witnessed
event, it is designed to provide
extra cues that might help to
jog witnesses’ memory for
more central details
Research has shown….
With the cognitive interview the average number of
correct statements produced by eyewitnesses was
41.1
With the standard police interview the correct
response rate was 29.4
https://www.youtube.com/watch?v=6kdVqpcd2mQ – watching this again,
could the interviewer have gone about the questions differently?
Evaluation
• Why would you advise police officers to use the Cognitive Interview
technique?
(Identify strengths and weaknesses)
• Original Fisher, Geiselman articles on the Blog
• Complete pg 34 in packs
• Exam question June 2012