Eyewitness Testimony

Question 1

Miscarriages of Justice

Answer 1

Eyewitness testimony errors involved in 75% of DNA exoneration cases

Eyewitness mistaken identification

Question 2

Eyewitness testimony is important

Answer 2

May be only evidence available if forensic is absent

Witnesses can identify and describe suspects to help with future investigations

Question 3

Eyewitness Testimony is persuasive

Answer 3

Eyewitness Testimony 78%
Fingerprints 70%
Polygraph 53%
Handwriting 34%

Jurors, judges and general public have limited knowledge of factors affecting eye witness testimony (Magnussen et al 2010)

Question 4

Eyewitness Testimony is error prone

Answer 4

Recorded crime on TV (Buckhout,1980)

2000 people rang in, but 1800 made incorrect ID.

Question 5

Megreya & Burton (2008)

Answer 5

Innocent suspect number 4 being chosen the most.

Question 6

Why are eyewitness unreliable?

Answer 6

Decision to attend to and encode stimulus properties - Poor encoding

Incorporate into internal representation (Schema) - Stereotypes and prejudice.

Integrate representation with additional information & regenerate representation (visualise) - Misleading information

Response - demand characteristics

Question 7

Factors that affect eyewitness accuracy

Answer 7

Eyewitness factors: emotional state, intoxication

Perpetrator factors: disguise, facial distinctiveness

Situtation factors: exposure duration, distance, retention interval

System variables: size, structure, and selection of fillers.
Cognitive interviews: procedures and training

Question 8

Encoding:
Ornstein et al, 2006
Holst and Pezdek 1992

Answer 8

We remember more of an event, the more we know about it in advance (Ornstein et al, 2006)

We remember more information that is consistent with our scripts (Holst and Pezdek, 1992).

Question 9

Change Blindness

Answer 9

Change blindness correlates with memory (Levin et al 2002) - Primed 65% versus not primed (12.5%).

Explanations (Simons,2000)
Overwriting, first impressions, nothing is stored, storage but no comparison and feature combination (Dog & Duck combined).

Question 10

Situation and perpetrator factors

Answer 10

Duration of exposure (Memon et al 2003)

distance from incident (Lindsay et al 2008)

Awareness of the incident

Facial distinctiveness (Busey & Tunnicliff, 1999)

Disguises (Patterson & Baddeley, 1977).

Question 11

Perps change of appearance and disguises

Answer 11

• Offender’s changed appearance and disguises

Study phase: Participants viewed a staged robbery. For 1/2 of the particpants the robber wore knit pullover cap.

Test phase: Identified perpetrator from video lineup 45% no hat group vs 27% hat group.

Question 12

Witness Factors

Answer 12

High stress negatively impacts memory (Deffenbacher et al, 2004)
- Soldier Study (Morgan et al 2004).
Ageing effect (Memon et al 2003).

Question 13

Witness Intoxication

Answer 13

Reduced attentional capacity

Alcohol myopia theory suggests that alcohol increases focus on central detail (Josephs,1990).

Question 14

Storage

Answer 14

Retention interval: delay decreases the amount of information that can be recalled

Post event suggestion

• Exposure to media report
• Co-witness discussions
• Choice blindness

Question 15

Retention Interval:
Face Recognition (Wells et al 2006)
Event details

Answer 15

Face Recognition

• Immediate, longer delays
• Fewer correct Ids
• Increase in false Ids

Event details

• Immediate vs 4 week delay
• Reduction in number of recalled facts
• % error consistent

Woman assaulted 36 years ago.

Question 16

Post event suggestion & misinformation

Answer 16

Many witnesses will see or read news of events.

• Recall vs what really happened
• Proneness to false memory associated with personality traits (Ost, Granhag & Hjelmsater, 2007).

Delay between event and information plays a role in acceptance of misleading suggestions -
Susceptibility of memories to retroactive interference increase as memories are forgotten (Reyna, 1995)

Question 17

Post event suggestion & misinformation P2.

Answer 17

86% of witness discuss their memory with co-witnesses

• Causes conformity (Gabbert et al 2004)
• Can cause misinformation (Wright et al, 2000).

Question 18

Difficulty detecting manipulation of a choice they made (Sagana et al, 2014).

Answer 18

Blindness for recognition decisions, this is the person you selected.

39 - 68% of detections remained undetected

Many people think they would be able to detect this manipulation

Question 19

Eyewitness Memory Typical reporting

Answer 19

Reported . Accuracy

Gender 100% 100%
Age . 55% . 38%
Speech . 15% 84%
Height . 75% . 44%

Question 20

Verbal Overshadowing

Answer 20

Most common: Hair Style

Less common: eye colour and eye shape, nose mouth and teeth.

Rarely mentioned cheek, chin and forehead

Question 21

Verbal Overshadowing Pt.2

Answer 21

When describing a face you become less accurate at recognising it subsequently (Schooler et al, 1990) reduction of 26%

(Meissner & Brigham, 2001) more likely to occur when identification immediately followed the description.

Question 22

Verbal Shadowing: Why does this occur? Schooler et al, 1990

Answer 22

No relationship between description quality and recognition performance.

Specific to verbal description, mentally revisualising the face does not interfere with recognition.

Question 23

Expert Processing

Answer 23

Unconscious
Non-verbal
Holistic
Good for face perception

Question 24

Inexpert Processing

Answer 24

Conscious
Verbal
Featural
Bad for face perception
Small Perceptual field

Question 25

Mugshots

Answer 25

Repeated exposure to a suspect increases probability of identification and confidence (Memon et al, 2002) - even if wrong

Building face composites can harm line up identification performance (Wells, Charman & Olson, 2005) - Reduction in chance of later identifying the original face.

Question 26

Similarity of fillers in line ups

Answer 26

Too highly similar = difficulty in identifying the suspect.

Moderately similar = higher identification and fewer false positives (Fitzgerald, Oriet & Price, 2015)

Question 27

Face Composite

Answer 27

Combining face composites yields improvements in face likeness (Bruce et al 2003).

• morphy of all four composites created a better likeness that individuals composites.
• 4 morphs performed better (produced more correct choices and fewer false positives) than individuals.

Question 28

Enhanced cognitive view

Answer 28

Mental context reinstatement, report everything, recall in a variety of temporal orders and change perspective.

Question 29

Enhanced Cognitive View: several stages of training

Answer 29

Very few police offices engage in it

83% interviews in UK are not done with the cognitive view (time consuming and pressures of resources are too great).

Question 30

Moving towards proactive approach: Post diction variables

Answer 30

Measurable variables that correlate with eyewitness accuracy

1. Individual differences
2. Self report decision processes
3. Response latency (how long to make identification

Question 31

Time Estimation

Answer 31

People vary hugely in time estimates, some being really poor judger of time (16% to 496% of actual duration).
But consistent across time estimations tasks.

Question 32

Face identification

Answer 32

Self-report measures of face recognition skill linked with identification accuracy for culprit (Olsson & Juslin,1999).

Self reports are subjective

Question 33

Eyewitness Testimony Summary

Answer 33

1. Estimator variables (eyewitness, perp, situation)
2. System Variables (legal & judicial process).
3. Postdiction variables (measurable indicators of accuracy).

Question 34

Eyewitness Testimony Summary: Psychologists have identified many factors that affect eyewitness testimony

Answer 34

Developed techniques to improve construction of photofits

Developed better line up procedures (Wells, Small, Penrod et al 1998

Developed the cognitive interview