Test 4- eyewitness testimony Flashcards
What is one of the earliest and most widely studied topics in forensic psych?
eyewitness evidence
3 stages of memory
- Encoding- perceive and pay attention to details
- Short term memory- limited capacity (either leaves memory or moves to LT memory)
- Long term memory- info accessed and retrieved as needed
T/F
Memory is like a videotape, exact representation of what has occurred?
FALSE
-memories can be influenced by subsequent events and sometimes is remembered inaccurately
T/F
Greater stress improves eyewitness memory
FALSE
-high stress can result in poorer memory
T/F
The race of eyewitness and perpetrator has an impact on identification accuracy
TRUE
-better able to correctly identify a member of their own race compared to a member of diff race (Cross race effect)
what is the weapon focus effect?
if a weapon is present, witness often focuses on it, and has less reliable memory for other aspects of the crime
What are two explanations of the “weapon focus” effect?
- Arousal (cue utilization)
- when emotional arousal increases, attentional capacity decreases and central details more likely to be encoded - Unusualness
- weapons are unusual and therefore attract attention
Describe the purpose of Canadas witness protection program run by the RCMP?
-protect individuals who provide police with info in investigation & prosecution of crimes when info places them at risk of harm (ST or LT)
Safer Witnesses Act- what was improved?
- makes easier for witnesses in provincial programs to obtain new identities
- imposes new restrictions on disclosure of info to help make program more secure
- increases amount of time emergency protection may be provided to witnesses
- makes program available to individuals referred from National Defence and CSIS
what most commonly leads to exonerations?
- corresponds with DNA evidence analysis, as was not originally available at the time and relied on eyewitness testimony
- 90% of exonerations come from physical evidence
Purpose of Innocence projects
-look at exonerations, 69% involving faulty eyewitness testimonies that lead to convictions
one with most numbers=255 exonerations
P. Devin
- went through 2116 past court cases with lineups and wrote report about importance of eyewitness identification in court
- 45% a suspect was picked, of these 90% brought to prosecution
- in 347 cases eyewitness testimony was only evidence, 75% were convicted
Study of mock jury
- corner store robbery and murder described to ppl, then asked to perform role of mock juror
- when add eyewitness testimony conviction rate rose from 18% to 72%, when evidence undermined conviction rate fell to 68%
issues with eyewitness’s before the event?
Expectations
-don’t expect crime to occur, may have internal biases about certain things which can influence the outcome
issues with eyewitness’s during the event?
Perception and attention
-there is evidence that you can modify how someone sees an event, which results in errors
issues with eyewitness’s after an event?
Decay of memory an interference
-can occur due to news reports (that can bias you) or may get questioned multiple times
what are 3 categories that testimonies can fall under?
- Accurate
- Unintentionally mistaken (these are most testimonies)
- intentionally deceptive
deice effect
tend to remember things that are associated but not actually mentioned/ occurred
Lab simulation to study eyewitness issues
- unknown participant views a critical event through slide sequence, video or live
- unaware they will be questioned until after witnessed event
- asked to describe what happened and perpetrator
estimator variable
-independent variable in lab studies examining eyewitness issues (can be manipulated)
=variable present at time of crime and cant be changed, accuracy can only be estimated after the crime (but under control of justice system)
system variable
-independent variable in lab studies examining eyewitness issues (can be manipulated)
=variables that can be manipulated to increase or decrease eyewitness accuracy, under control of justice system
open ended recall (free narrative)
asked to write or orally state all they remember about event without officer asking questions, may be asked to describe perpetrator
direct question recall
asked series of specific questions about crime or perpetrator
what is witness recall used to examine?
amount of info reported, type of info reported and accuracy of info reported
quantity and accuracy of descriptions
- descriptions limited in detail and accuracy
- witnesses in real crimes report fewer details then stages crimes
- gender and hair color most accurately reported, age least followed by shoe and height
- use of standard did not improve accuracy
- writing descriptions produced shorter and less accurate descriptions compared to verbal descriptions
recall memory
reporting details of previously witnessed event or person
recognition memory
determining whether a previously seen item or person is same as what is currently being viewed
estimator variable research in recognition memory
age: older adults make fewer correct identifications and fewer correct rejections from lineup
race: cross race effect/ other race bias (witness remembered faces of ppl of their own race with greater accuracy)
explanations of cross race effect
- Attitudes: ppl w/ fewer prejudicial attitudes may be more inclined to distinguish among members of other races
- Physiognomic homogeneity: some races have less variability in their faces
- interracial contact: amount/ type of contact ppl have had w/ other races
false memory
remembering things that didn’t occur (not lying). They believe it happened but really didn’t