Eyewitness testimony- criminology

eyewitness testimony definition

• when a crime is committed and the identity of the perpetrator is unknown, the victim(s) or witness(es) to the crime may be asked to attend an identification parade to identify police suspect (Wilcock et al., 2008)

• refers to the account given by individuals who have witnessed a crime, often used to identify suspects in legal proceedings.

eyewitness testimony pros and cons

• not a passive recording of events but rather a reconstructive process

• memory is distorted by cognitive, situation and procedural factors

• can be valuable, highly persuasive, frequently relied upon court

• often unreliable, prone to error, significant implications for wrongful convictions

memory reconstructive

• memory reconstructive nor reproductive

• do not store exact copies of events

• reconstruct memories using schemas and prior knowledge

• misinformation effect, post-event information alters memory

Loftus and Palmer (1974)

• showed how leading questions can distort recall

experiments memory reconstructive

• most research laboratory experiments lack ecological validity

• in real life emotionally intense, impair or enhance memory

• memory distortion genuine concern

factors affecting accuracy, situational

• anxiety

• weapon focus effect

• cross-race effect

• post-event discussion

anxiety

• Yerkes-Dodson law

• moderate levels of anxiety may enhance performance

• high levels can impair memory

• a violent crime, extreme stress can reduce ability to accurately encode details

weapon focus effect

• attention drawn to weapon

• reduce ability to recall other details i.e. face

cross-race effect

• individuals are less accurate at identifying faces of different racial group

• increase risk of misidentification

post-event discussion

• witnesses may incorporate misleading information from others into their own recall

eval factors affecting accuracy

• findings experimental and field

• witnesses affected differently

• individual difficulties, confidence, prior experience influence accuracy

• eyewitness identification highly vulnerable to error

system variables

• how identification parades are conducted

• parade can influence decisions if poorly designed

• may feel pressured to choose someone even if the perpetrator is not present

• this is a relative judgement

• mistaken ewi leading cause of wrongful convictions

• evidence from DNA exoneration cases demonstrated that wrongful convictions based on inaccurate ewt

• real-world support eat is unreliable and can have legal consequences

system variables results

• these issues led to improvements in legal procedures

• while flawed not totally without value when handled appropriately

improvements

• cognitive interview

• reforms in police procedure

cognitive interview

• encourages witnesses to recreate context of event

• report all details

• recall event from different perspective

• enhance recall without dramatically increasing false information

reforms in police procedure

• double-blind line-ups

• clearer instructions to witnesses

• implemented to reduce bias

• practical value psychological research in improving reliability of eyewitness evidence

eval of improvements

• methods not consistently applied

• effectiveness can vary depending on context

• with improvements, risk of error can not be eliminated

conclusion of ewt

• powerful

• flawed due to the reconstructive nature of memory

• influence cognitive and situational factors

• susceptible to distortion

• serious consequences i.e. wrongful convictions

• improvements don’t fully overcome limitations of human memory

• treated with caution and supported by additional evidence where possible

citations

• Loftus and palmer, 1974

• wells, 1978

• yerkes and Dodson, 1908

• wilcock, bull and vrij, 2008