1. Eyewitness testimony
The problem is clear: the unreliability of eyewitness identification evidence poses one of the most serious problems in the administration of criminal justice and civil litigation.
~ Elizabeth Loftus

2. Testimonial or Direct Evidence
Eyewitness accounts can provide important  evidence leading to the arrest of a criminal
This also heavily influences the jury
However, witness testimonies may be flawed
How much does an eyewitness really  remember?
the crime scene may have been too  dark
the witness may have been distracted by a  weapon
the longer the time between the incident and the  interview, the more a witness  can forget
New info can influence a testimony and  actually  change memories
mug shots, news reports, leading  questions, etc.

3. Police have to be able to judge if an eyewitness is reliable
Police have to be able to judge if an eyewitness is reliable.  Here are some things to consider:
The type of crime and how  the witness saw it.
a witness who is  physically similar to an  offender tends to  remember more details
victims of serious crimes  tend to remember more  details over a longer  period of time, because  they relive the event
the presence of a  weapon can also affect  memory

4. Witness Attributes Attributes associated with eyewitness accuracy
Stress
Moderate levels of stress tend to enhance eyewitness memory.
Orients witness to the event and increases attention.
Severe stress decreases eyewitness accuracy.
More likely to provide inaccurate reports and to make false ID.
Decreases ability to encode information.

5. Witness Attributes Attributes associated with eyewitness accuracy
Alcohol/drugs
Intoxication at the time of the event impairs memory ability.
Can decrease perceptual abilities.
Interferes with ability to store information.
Decreases ability to recall information at later time.
Increases likelihood of false ID.

6. Witness Attributes Attributes associated with eyewitness accuracy
Age (children, elderly)
Memory ability is fairly stable across the lifespan.
Children (up to early teens):
More susceptible to suggestive questioning & misinformation.
More likely to make an ID, leading to increased likelihood of false ID. Children over 4 are as accurate as adults when the target is in the line-up
Children and the elderly less accurate than adults when target is not in the line-up
Older children recall more than do younger children
Younger children forget more rapidly
Children more suggestible than adults
Experts cannot tell the difference between accurate and inaccurate statements made by children
Elderly (~60 and above):
More likely to make a false ID.

7. Witness Attributes
Attributes that ARE NOT associated with eyewitness accuracy
Occupation
Police officers are no more accurate than laypersons.
However, they tend to provide more useful descriptions.
Gender
Men & women do not differ in abilities.
Witness/victim status
Victims & bystanders do not differ in abilities.
Any difference between a victim & bystander is likely due to other aspects of the witnessing event.
E.g., increased stress, viewing distance, perpetrator- familiarity, etc.

8. Other Witness Factors that MUST be Considered
Did the witness already know the a ccused?
What was their relationship?
How much time passed between  the offense and the identification?
Had the witness already identified  (or failed  to identify) the  defendant?
Has the witness already identified  someone  else?
Most cases of an innocent person  being convicted is due to mistaken eye witness identification!

9. Interviewing techniques  or how  information is retrieved can alter the  accuracy of an eyewitness' story
eyewitnesses tend to be more accu rate  answering questions about wh at happened  than what the  offender looks like
open ended questions tend to get  better descriptions
"What did the offender look  like?" vs "What  color shirt was  he wearing?“
Leading questions lessen accuracy
"Was the offenders shirt red?“
A confident witness is more  accurate

10. Good Interview Practices
Record both the questions asked as well as the answers
Have the witness tell the story from beginning to end; from the end to the beginning;
Have the witness tell the story from different perspectives (victim, other witnesses, perp)
Follow-up with specific questions
Elicit partial information

11. Avoid Leading questions (reconstructive memory)
Asking questions in a rapid-fire manner
go slow
give the witness time to think
Asking the same questions more than once
Multiple-choice questions
Interrupting the witness
Nonverbal cues or paralanguage indicating your opinion

12. Good Interview Practices
Get statement as close to the event as possible
Place the witness in the event environment
Before asking questions, ask the witness to recreate the incident in his/her mind
Start with unprompted recollection
use open-ended questions
Tell the witness
that they should do most of the talking
not to edit their thoughts; they should say whatever comes to mind

13. Reconstructive Memory Questions Change Memory
How fast were the cars going when they ____ each other?
Contacted
Hit
Bumped
Collided into
Smashed into

14. Speed estimates for the verbs used in the witness question
Estimated Speed
41mph
39mph
38mph
34mph
32mph
Contacted
Hit
Bumped
Collided
Smashed

15. Persuasiveness of Eyewitnesses
Most persuasive form of evidence
Eyewitnesses believed 80% of the time
Juries cannot tell the difference between an accurate and an inaccurate witness
Accurate witness believed 68% of time
Inaccurate witness believed 70% of time

16. Eyewitnesses are Most Persuasive When
They provide detail (trivial persuasion)
They are confident
They are adults
Children can be persuasive under certain circumstances
Elderly are perceived similar to children

17. Eyewitnesses are the Most Persuasive Form of Evidence - Loftus (1983)
Type of Evidence % guilty votes
Eyewitness testimony 78
Fingerprints 70
Polygraph 53
Handwriting 34
These slides show how persuasive eyewitness testimony is. I like to include the old Loftus stuff to show the history of this type of research.

18. Eyewitness Accuracy via Academic Research
Buckhout (1975)
Simulated crime on a TV newscast
2,145 callers
14.7% were accurate
Buckhout (1974)
Staged assault on professor in front of students
7 weeks later, students shown line-up of six photographs
40% identified attacker
36% identified bystander
23% identified person not there

19. Eyewitness Accuracy Cromag (1996)
Boeing 747 crashed into an 11-story building in Amsterdam
TV footage showed rescue attempts after the crash
66% of students “remembered” seeing the plane actually hit the building

20. What do Witnesses Report? Fashsing, Ask, & Granhag (2004)
Attribute
% Reporting
% Accurate
Gender
99.6
100
Height
91.2 44
Clothing (upper body)
90.8 58
Clothing (head)
89.6 56
Build
84.4 57
Weapon
76.4 71
Clothing (pants)
73.6 53
Age
62.4 38
Type of speech
46.8 84

21. Common Errors Overestimate the height of criminals
Overestimate the duration of a brief event
Notice more about the action than the person
Pay more attention to the weapon

22. 333 people have been exonerated through DNA.
Eyewitness misidentification played a role in over 75% of convictions overturned by DNA.

23. Contributing Causes of Wrongful Convictions