Expert Witness and Eye Witness Memory Flashcards
Expert witness definition
A person with specific knowledge in a particular subject relating to the criminal case.
Conley Case
Policemen in Boston were chasing a criminal. Black policeman was shot by white policeman as they thought he was suspect since they were all in plain clothes
Chabris et al (2011)
Experimental re-inactment of the Conley case. At the side was a fight between students. At night only 35% said they saw the fight and at day about 56%.
Kassin et al (2001)
Surveyed 64 psychologists about 30 eyewitness phenomena including stress, weapon focus, line-ups etc.
Mars and Farmville Murders
Horror-core musician that acted as an expert witness in the Farmville Murders, as the murderer was a fan of his music so he could give in depth on what methods could have been inspired by him.
Eyewitness definition
The source of evidence - what they saw, what they heard, what they know first hand.
Testimony definition
Evidence given by a witness/victim, usually under oath giving their recollections of circumstances and descriptions of events and people involved.
Not opinion.
Innocence Project
Using DNA analysis on old solved cases to test whether the person arrested through eyewitness testimony was guilty
Garrett (2017)
Misunderstanding of how memory works can lead to a wrongful conviction.
Wells et al (1998)
Mistaken eyewitness identification is responsible for more wrongful convictions than all the others combined.
Found 40 criminal cases where DNA proved innocence, and 36 of the cases involved at least 1 eyewitness.
Munsterberg (1908)
Identified drawbacks of eyewitness testimony.
More confident people tend to be believed more even if less accurate.
Neisser and Winograd (1988)
Ecological approaches to memory.
Loftus and Palmer (1974)
Post event factors
Wells (1978)
System-Estimator Variables
Estimator variables - Uncontrollable, therefore their impact has to be estimated.
System variables - Procedures can produce or prevent systematic bias.
Bartlett (1935)
Our memories are records of our experiences and interpretations of events, not records of the events themselves. They are reconstructed.
Things that could effect encoding of an episodic memory
- Stress
- Attention
- Stereotyping
- Intoxication
Things that effect the storage of an episodic memory
- Post-event information
- Delay
- Trauma
Things that effect the retrieval of an episodic memory
- Investigative procedure
2. Questioning techniques
Valentine and Mesout (2009)
Stress associated with worse recall.
Morgan et al (2013)
Did a mock prisoner of war camp and found that prisoners were more susceptible to false information
Hope et al (2016)
Observers have better recall than those directly at risk in simulated armed police operations
Yuille and Cutshall (1986)
Witnesses to a real crime showed a positive relationship between stress and accurate recall even after 5 months
Fawcett et al (2013)
Weapon focus - tendency to forget other details when weapon is present
Erickson et al (2014)
Unusualness hypothesis - Memory not effected by the weapon but rather unusualness.
Participants who served drinks to a man with either a gun, an empty glass or a rubber chicken were more likely to chose an innocent suspect more often after seeing either the gun or the chicken, but were no less likely to correctly choose the perpetrator after seeing the chicken.
Tuckey and Brewer (2003)
Tendency to misremember schema incongruent information about crimes.
Deffenbacher (1983)
10 studies show increased or stable accuracy with higher levels while 11 show the opposite.
Deffenbacher et al (2004)
High levels of stress impaired accuracy and recall on both types of eyewitness memory
Shapiro and Penrod (1986)
Hit rate increases with time spent viewing the target. However, increased exposure increases false alarms
Read (1995)
Longer exposure may bias people’s assumptions about what they should remember.
Memon, Hope and Bull (2003)
Simulated a crime and manipulated witness exposure. Longer exposure caused higher accuracy but also inflated witness confidence.
Memon et al (2003)
90% of mock witness said they expected the culprit to be present in line-up
Wells (1993)
54% of those who correctly identified the culprit in a line-up said they’d have identified someone else if culprit wasn’t present.
