Week 3: Eyewitness Identification Flashcards
What is the purpose of a lineup?
To see if the witness recognises the suspect
What are the determinants of identification reliability?
The lineup requires the eyewitness to match lineup members to memory and this decision results from this matching process
The outcome of this matching process is influenced by:
- quality of eye witness memory
- characteristics of the lineup
What conditions need to be considered regarding EW memory encoding?
Viewing conditions
- Duration: longer = stronger memories and more reliable evidence
- Distance: closer = stronger memories
Divided attention
- Weapon focus: presence of a weapon during a crime affects ability to accurately identify offender as it is a highly salient stimulus that grabs people’s attention, and they pay less attention to the person holding it
What is interesting about EW account of distance during crime?
People are really bad at assessing the distance between themselves and a perpetrator
In some cases, overestimating by 50 metres
What are the issues of memory storage in eyewitnesses?
The length of retention is important as memory fades over time
As time passes, there is also increased chances to interact with other witnesses that may influence or contaminate what they remember
It is rare for lab studies to test such long recall, in the real world it can be weeks, months or longer. However some studies have found correct IDs after a duration of time
What is a common occurrence (with culprit) whilst waiting weeks/months to ID?
Natural change in appearance, basic changes as people age. Not unreasonable.
How does changes in appearance affect ID accuracy?
Study: natural change over 4 years
Failures to ID the culprit increase
Correct ID’s decrease
What about deliberate natural changes?
These are things such as having a haircut or shaving off facial hair
- causes a decrease in correct ID’s
- increase in incorrect rejection
What is replication and concealment in a lineup?
Using editing software to edit a distinctive tattoo onto other lineup members or to conceal the same area on everyone
What are the problematic assumptions of EW?
They assume they have a suspect and that the suspect is guilty (assume evidence)
An expectation is created that the guilt person is there and they have to pick them (primed to pick)
Wants to pick and if don’t have the right memory cues, they rely on environmental ones
What are the environmental cues that an EW might rely on in the absence of memory cues?
Body language, suggestion etc
These can be intentional but are more often unintentional
What are the recommendations for lineup administrations?
Double blind: EW and administrator should not know who the suspect is so that they don’t unintentionally influence ID
Unbiased instructions: nothing to imply culprit is present, don’t emphasise the importance of making an ID, not giving a ‘not present’ option
What are some problems with double blind lineups?
It’s not practical - small police stations make it hard to find a police officer who doesn’t know
The investigators of the case may be reluctant to hand over the administration to someone else as they want to make sure it is done right
What is a way to combat problems with double blind lineup administration?
It can be done in a computerised way - don’t even need administrator
What is the affect of adding the line ‘the culprit may or may not be in the lineup’ to lineups?
It has the ability to cut false identification rates in half.
Shows the importance of cognitive factors
Why should suspect photos be arranged in a circular way?
People typically guess the middle person in an array. They believe these to be hiding places
80% of the time, police officers will place the suspect in the middle.
Needs to be randomised and the EW should be told this.
What is a bias in lineups resulting from composition and size?
You need a number of plausible candidates!
Select foils that either match physical similarity or match description
What happens if candidates are too similar?
It creates an impossible memory task
What are some problems what it comes to selecting foils?
The quality of descriptions provided by EW: may not report all they remember so items not cued are difficult to articulate. A lot of potentially important details don’t make it into the description
Additional details may be cued during recognition: what is the likelihood of an innocent suspect randomly sharing these details
So should we match description or similarity when choosing foils?
Match-description is generally but not universally favoured
Probably require elements of both approaches
What are the lineup presentation methods?
The show up
Simultaneous lineup
Sequential lineups
Explain the show up presentation method?
Take a picture and show it to the witness this is the simplest way
An enormously suggestive procedure it conveys that it is the suspect and that there should be some level of evidence
Explain the simultaneous lineup presentation method
Show many photos simultaneously
With a reminder that they may or may not be there
Promotes relative judgements
Explain absolute and relative judgement
Absolute judgements are comparing memories to the person in the lineup and engaging the degree to which they match
Relative judgements are considering all of the people in the lineup and which is the closest match this is a problem if the perpetrator is absent
What is the evidence for relative judgements
Similar choosing rates when the target is present and when the target is absent
What are sequential lineups
Showing members one at a time then deciding yes or no
Why is it good to use sequential lineups
They promote absolute judgements and reduce the reliance on relative judgements
What are the effects of sequential lineups as determined by meta analysis
Lower choosing rates
Correct identifications = same or lower
Fewer false ID’s
When is the sequential advantage more pronounced in sequential lineups and what is the process
When lineup size is not known in advance
This is called Backloading where you hide how many photos are left this works on the underlying assumption that the perpetrator is present somewhere and removes the mechanism where the witness gets more likely to pick as we get towards the end of the lineup
What percentages does the most recent study attribute towards EW identifying fillers?
Sequential lineups 30% of all IDs are fillers
For simultaneous lineups 41% of all ID’s are fillers
These error rates are still too high
Overall what can we say eyewitness memory and identification reliability are shaped by
The conditions in which the memory was formed and the conditions in which the memory was tested it is often an interaction between these two
Psychologist cannot determine ID accuracy but can talk sensibly about reliability
What is the role of confidence in eyewitness identification
Confident identifications are more persuasive and are more likely to be believed
In mock juror Studies when we manipulate confidence identifications - more believable
What is the relationship between confidence and reliability of information
There are good theoretical reason such as confidence is tied to memory strength therefore and more reliable identification
There is a strong linear relationship between the percentage of correct identifications and the eyewitness confidence
When does Confidence need to be measured
Immediately after the decision is made
What else increases confidence in an eyewitness
Preparing them for cross-examination increases their confidence also telling them that a co-witness identified the same suspect, telling them they identified the correct suspect increases their confidence
