Eyewitness Memory Flashcards
What’s the order of a criminal investigation?
Crime event Police investigation Guilty suspect = target present lineup OR Innocent suspect = target absent lineup
How prominent is eyewitness misidentification?
Played a role in over 70% of convictions
What are common beliefs about memory
It works like a video recorder
However, memory is both a reproduction and reconstruction of past events
What is the primary effect?
Tendency to remember the first piece of info we encounter better than I of presented later on
What is the regency effect?
More recent info is better remembered
Loftus and palmer
Experiment 1
- about how fast were the cars going when they hit (contacted, collided, etc) each other
Experiment 2
- did you see any broken glass (there was none but different verbs above affected yes/no)
Common misconceptions with eyewitness testimony?
Textbooks - inherently unreliable
Eyewitness memory can be reliable as long as it is not contaminated by other extraneous factors
Therefore crucial to elucidate which factors may or may not affect eyewitness memory
What are the stages of memory?
Input
Encoding
Storage
Retrieval
What is memory?
The means by which we draw on our past experiences in order to use this info in the present
What’s recall?
Measure of memory in which the person must retrieve info learned earlier
What is recognition?
Measure of memory in which the person need only identify items previously learned
What are estimator variables?
Factors that cannot be controlled by the criminal justice system
Light conditions Weapon presence Disguise Exposure duration Stress/arousal Eyewitness characteristics Defendant characteristics
What are system variables?
Factors that can be controlled by the criminal justice system
Interviewing procedures
Identification procedures
Lineup instructions, format, and presentation
Facial composite procedures
Estimator variables and their effects on encoding?
Light conditions
- correct target present identifications are very unlikely following observations made in low lighting at 20m
Weapon focus effect
- weapon presence often leads to reduced identification accuracy
Disguises
- identification accuracy generally decreases with degree of disguise (e.g. stocking mask, sunglasses)
How does storage affect memory?
Retention interval
- Eyewitnesses typically present lower hit rates and higher false alarms with the passage of time.
Co-witness discussion
- co-witnesses can often incorporate external info into their accounts, even if they had not seen that info before
How do system variables affect retrieval?
Interviewing procedures
- suggestive interviewing protocols may contaminate eyewitness memory.
- Some techniques can enhance memory recall (cognitive interview)
- cognitive technique
- question type
- rapport building
- room setting
Identification procedures
- elements in the construction and presentation of lineups influence eyewitness decisions
- lineup size
- lineup presentation
- lineup formation (photo, video, live)
- filler selection
- positive identification feedback
What is expert testimony?
The delivery to a jury by a qualified research psychologist of info about research and theory on eyewitness behaviour
Based on the assumption that expert testimony will increase juror sensitivity to the factors that influence eyewitness identification performance
Often causes jurors to become overly sceptical of eyewitness evidence
What are judicial instructions?
Judge presents the jury with information about the psychology of eyewitness identifications
Typically produces confusion or scepticism
What are teaching aids?
PowerPoint preventions in which triers of fact are taught to consider whether:
- the eyewitness interview procedures were conducted properly
- the identification procedures were conducted properly
- there were any factors present during the crime that might have have negatively affected the eyewitness memory
Some initial promising results regarding the evaluation of eyewitness evidence
Limitations of eyewitness research?
Lab experiments hardly reproduce the high stakes situations present in eyewitness context
Ppts are many times aware that the study will involve some sort of memory test (deliberate encoding). In real life situations individuals are typically not aware they will witness a crime (incidental encoding).
Most studies include very short retention intervals (time between encoding and retrieval), which compromises on ecological validity given that in many cases witnesses will provide their testimony days or weeks after the crime has occurred.
Identification guidelines?
Blind administer, with ID training administers lineup
Tell witness perpetrator may or may not be present
Reasonable size and foil similarity to fill lineup
Record confidence immediately after ID
Videotape the ID process
Lineup sizes?
12 - UK
6 - USA
3 - Russia
How to do filler selection?
The suspect should not stand out in the lineup
Fillers should her equally good alternatives to the suspect
Why is filler selection important?
If fillers do not sufficiently resemble the suspect, it increases the risk that an innocent suspect will be misidentified
If fillers resemble the suspect too strongly, even witnesses with good memory of the witnessed event will be unable to identify the culprit.
Lineup administration?
Caution that the offender might not be in the lineup
- they’re not failing if they do not choose someone
- we got the guy. We just need for you to come pick him out of a lineup
What’s double blind testing?
Prevent the lineup administrator from unintentionally influencing the outcome of the results
Videotape the ID process
Live, photo or video lineups?
Based on available research, there is no reason to believe that live lineups, videotaped lineups, or phot arrays produce substantial differences in identification performance
What’s simultaneous presentation?
Lineup members are shown all at once
Allows comparison between members
Theorised to encourage witnesses to select the best match, relative to the others
What’s sequential presentation?
Lineup members viewed one at a time
Decision may or may not be made before proceeding
Theorised to discourage comparisons between members, encouraging witnesses compare each member to their memory of the culprit
Usually present less correct identification but also less false alarms
Decision time?
The faster an eyewitness is in making an identification, the more likely the identification is to be accurate.
The 10-12s rule for accurate identification
Decision process?
Accurate witnesses were more likely to show automatic recognition (e.g. his face just popped out at me)
Inaccurate witnesses were more likely to adopt a process of elimination strategy (e.g. I compared the photos to each other to narrow the choices)
Lineup identification test?
Predictive utility of face recognition tasks for eyewitness identification
Proclivity to choose predicted mistaken identifications on culprit-absent lineups
Face recognition skill was only weakly predictive of correct identifications in culprit-present lineups
Good indicators of eyewitness ID accuracy?
Confidence
Decision time
Decision process
