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
Porter, Yuille & Lehman (False memory study)
PURPOSE: to study implanted false memories in adults, wanted to see if can implant something emotional, and see if observer can tell difference between real events, fabricated and false implanted memory
METHOD: 77 participants, questionnaire sent to parents asking about a real memory, memory for implantation, and fabricated one. Want to see if parents and participants memories match up. Researchers first focused on real and implanted memory and see if differ, encourage memory and tell them it is real. In last interview given envelope and told will get reward if convince questioner that the event occurred.
RESULTS: most participants immediately recalled real event, 20/77 recalled a false memory, 34/77 had no recall whatsoever of false memory
criteria for a false memory in Porter, Yuille & Lehman study
- participants reported remembering the memory
- agree to and incorporate cues provided by experimenter
- incorporate additional info beyond that provided by experimenter
- cant have been remembered on its initial presentation
- have to say they didn’t discuss with parents
recovered memory
-repressed from when event occurred, now have unlocked (doesn’t suffer from interference or decay as it was locked away
repressed memory
when event occurred, your mind immediately locked it away and don’t have awareness of it at all
how was multi-personality thought to be associated with repressed memories
thought that sexual abuse repressed memories which locked away a whole personality
Nick Spanos
- showed that there are therapist induced disorders
- demonic possession (catholic vs protestant possession differed) those who claimed they were possessed differed in symptoms
Pathis (2014) study
Are memory wars over?
- public & alternative therapists generally believe that traumatic memoires often repressed and can be retrieved in therapy accurately
- clinical psychologists don’t believe it occurs (hard to find a case that supports repression of traumatic memories and retrieval)
flashbulb memory
- an impression may be so exciting emotionally as to leave a scar on cerebral tissue
- usually a cultural event where lrg proportion of pop witnesses and are impacted by the event (doesn’t have to be a tragedy)
- memories usually hard to measure as don’t have ground truth
Neisser and Harsch (1992)–> flashbulb memory study
-study of memories of the Challenger disaster
METHOD:
- initial questionnaire provided on morning after event including important questions and their confidence levels (taken as ground truth)
- 2 yrs later received same questionnaire, then go through extensive interview to see if can recover memories), then shown original questionnaire
RESULTS:
- weighted accuracy; most not very good
- confidence rating: most very confident
- accuracy didn’t improve after follow up interview
- no one changed memory to what questionnaire said
- correlation amongst vividness and intensity of memory with accuracy of statement
confidence in memories
- US court ruled confidence is directly related to veracity (some judges tell juries)
- general research shows there isn’t strong relationship
- initial unbiased police interviews immediately after an event- peoples confidence is somewhat related to memory
How can eyewitness evidence become contained?
- Query construction (open ended not leading)
- leaking between individuals
- poor recording
- rookies
Elizabeth Loftus
found that witnesses reports can be altered by phrasing of questions
Misinformation effect (post-information effect)
=witness presented with inaccurate info after an event will often incorporate that misinformation into subsequent recall task
what are 3 hypothesises for the misinformation effect ?
- Misinformation acceptance hypothesis=guessing or experimenter pleasing
- source misattribution hypothesis= remember correct and incorrect answer, but don’t remember where each came from
- memory impairment hypothesis= original memory replaced or altered by new incorrect memory
hypnosis in regard to memories
- may be able to remember a greater amount of info (hypnotically refreshed memory) but just as likely to be inaccurate as accurate
- Canadian courts typically don’t allow evidence gained through hypnosis
what are two techniques used in hypnosis to help with eyewitness memory?
- age regression
- go back in time and re-experience event - TV technique
- witness imagines that they are watching an imaginary tv screen with events being played
what is the best style of interview?
Cognitive Interview
4 memory retrieving techniques to increase memory recall?
- restating the context
- reporting everything
- reversing order
- changing perspective
Cognitive Interview (5 main elements)
- Rapport Building (make feel comfortable)
- supportive interview behaviour (free recall, don’t interrupt)
- transfer of control (let them take control)
- focused retrieval (open-ended questions after free recall, focus on retrieval, let questions stem from info provided)
- witness- compatible questioning (ask questions in style of how witness thinks about things)
showup
alternative identification procedure where show one person to witness: the suspect
- problematic as no other suspects, so witness is aware of who police suspect to be suspect
- should only be used for deathbed identification or if suspect immediately apprehended at or near scene of crime
how does showing a photo prior to lineup affect identification?
accuracy goes down if seen photo prior
what is the purpose of a lineup?
- View group of possible suspects and determine whether one is the perpetrator
- Identification increases likelihood the suspect is the perpetrator, also provides police with info about what perpetrator looks like based on person selected
suspect
=person the police suspect committed the crime (guilty or innocent of crime in question)
perpetrator
= guilty person who committed the crime
foils or distractors
lineup members who are known to be innocent of the crime
Similarity-to-suspect strategy
match lineup members to suspects appearance
Match-to-description strategy
sets limits on number of features that need to be matched (only match items witness provided)
fair lineup
- suspect doesn’t stand out from others
- Should also include distractor with characteristics described if suspect doesn’t have them
how many suspects should be present in a lineup?
should only contain 1 suspect
what is a double blind lineup?
- Person showing lineup shouldn’t know who the suspect is in the lineup
- this is the preferred administration method for lineups
what is a specific instruction that should be provided to witnesses when choosing from a lineup?
witnesses should be informed that suspect may not be present in lineup
what should be recorded immediately following the identification decision when performing a lineup? (4)
- ensure record of witnesses exact identification response
- confidence in decision
- decision latency
- other perceptions that witness had of the encoding and identification experiences
target present lineup
-lineup contains perpetrator
- correct rejection= identifying guilty suspect
- foil identification= identify a foil
- false rejection= state perpetrator not present (issue as guilty person will not be prosecuted)
target absent lineup
-substitute perpetrators picture with another photo
- correct rejection= state not present
- false identification= identify innocent suspect (issue as innocent might be prosecuted and guilty goes free)
pros of a photo array lineups (5)
-more common than live lineups
- less time consuming to construct
- portable
- suspect doesn’t have right to council being present when witness looks at photos
- Photos are static so don’t have to worry about behavior drawing attention
- Witness may be less anxious
pros of a video lineup
-can enlarge faces and focus on particular features
simultaneous lineup & what kind of judgment encouraged?
- presents all members at one time
- Suggests it encourages the witness to make a relative judgment (compares members to each other)
sequential lineup & judgment associated?
- present members serially to witness (make decision before seeing next)
- Make an absolute judgment= compare to memory
- higher correct rejection rate
Brewer et al (2012)
“A new kind of lineup”
- tried to solve problems in lineups, wanted to create different kind of lineup
- used confidence judgements under deadline pressure (2s to look, 1s to respond)
- used sequential photo administration, in end whoever most confident about is the perpetrator
- accuracy increased for 11 to 38%
- not used a lot as rejected by prosecution (defence can use as evidence as somewhat confident about other suspects)
walk by
- naturalistic environment
- witness taken to location where think suspect might be, when they pass ask witness if can see the perpetrator
lineup bias
suggest whom police suspect and thereby whom the witness should identify
name 3 types of lineup biases
- Foil bias= suspect is only lineup member who matched description of perpetrator
- Clothing bias= suspect is only one wearing clothing similar to that worn by perpetrator
- Instructional bias= police fail to mention to witness that perpetrator may not be present; rather imply they are present
expert witnesses in eyewitness cases
- courts reluctant to accept b/c juries already know all of this
- questionable if lab studies can generalize
what are 3 features of lab studies that make it questionable as to if they can generalize
- studies examining the same issue produce various results
- most studies are university students, real-life witnesses vary in age other demographics
- most studies allow a witness to view perpetrator for approx. 6 seconds; in reality may view for five or more minutes
Orchard Yarmey (1995) "voice identification study"
- listen to tape of mock kidnapper (varied in length, distinctiveness and tone)
- Identification accuracy higher for longer voice samples
- Whispering significantly decreased identification accuracy
- Distinctiveness interacted with whispering, influencing identification accuracy
what helps improve accuracy of voice recognition?
laughter
Factors that decrease accuracy of voice identification( 3)
- Likelihood of correct identification decreased if voice changed by whispering or muffling, or through emotion
- If target voice presented later in lineup, correct identification decrease
- Trend to be more accurate when speaker has familiar accent
