Eyewitness Testimony

  • Major role in whether a defendant is convicted
  • No eyewitness testimony – conviction rate 18%; with eyewitness testimony – conviction rate 72%
  • Problem
  • Often incorrect
  • DNA exoneration cases (Scheck, Neufeld, & Dwyer, 2001)
  • Includes
  • Information concerning people
  • Victim, perpetrator, other witnesses
  • Information concerning the crime event
  • Action sequence, includes what was said, what was done, and what was in the environment
  • Why incorrect?
  • Memory problem
  • Must accurately report a lot of information
  • Memory is not like a video

Memory

  • Two parts
  • Encoding
  • Information from our environment that is processed/transferred into memory
  • Retrieval
  • Process of accessing stored memories

Memory Problems: Eyewitness Research

  • Incomplete/ Vague Memory * Poor memory for details
  • Penny Study
  • False Memory
  • The Misinformation Effect (Loftus)

Memory Problems: Incomplete/ Vague Memory

  • “Penny study” (Nickerson, et al., 1979)
  • Most people could not correctly identify a penny
  • Very familiar object * Suggests that we do not encode all details (i.e., memory is not a photograph) * Encode useful details

Memory Problems: False Memory

  • Misinformation Effect (Loftus)
  • Incorporating “misinformation” into one’s memory of the event after receiving misleading information about it

Eyewitness Situation Example

  • Witness a crime * Talk to other witnesses
  • (E.g. did you see what type of gun was that he had? That tattoo on his neck looked like a dragon didn’t it? I can’t believe he threatened to stab the little girl. Etc.)
  • Overhear police investigation
  • Give statement to police
  • Did he threaten any by standard with a weapon?
  • Where there any distinguishing marks on his body?
  • What did the gun look like?
  • Hear news reports concerning the crime * Repeat information for friends, family etc.
  • Provide the court with a personal statement
  • Problem
  • Only include information that YOU witnessed* Exclude information from
  • Other witnesses
  • Police
  • News, Internet, newspapers

Misinformation Effect Explanation

  • Source Monitoring Framework (Johnson)
  • Determining the origin of a memory
  • Separate from memory for content
  • Did I hear this joke from Susie or Mark?
  • Did I take my morning pill or just think about doing so? * Did I learn that Brittney Murphy died from a TV show or the Internet
  • Very difficult

Eyewitness Memory Summary

  • Eyewitness Testimony is very influential, but often incorrect
  • Memory Problem
  • Must recall information about the people and crime event
  • Memory Basics
  • Encoding- Learning* Retrieval- Remembering

Eyewitness Memory   Summary

  • Eyewitness Research – Two memory deficits * Memory can be incomplete/lack detail
  • Memory can be false
  • Misinformation Effect
  • Misinformation Effect
  • Incorporating new information into an event that has transpired
  • Why/How
  • Source Monitoring Framework
  • Memories do not have tags telling you their origins
  • Determining the source of a memory is a judgment process

Eyewitness Suggestibility Research

  • Phenomena that affect eyewitness testimony * For events
  • Guided Imagery
  • Interrogation Wording

Eyewitness Suggestibility –Guided Imagery

  • Guided Imagery
  • Therapist asks you to recall/ or imagine specific circumstances
  • Sexual and childhood abuse
  • Problem
  • May imagine events that never transpired
  • Can lead to imagination inflation
  • Imagination Inflation
  • Imagining information increases the probability of reporting imaginary object or sequence of events as real

Eyewitness Suggestibility – Imagination Inflation

  • How/ Why
  • As you repeatedly imagine an object or event the following increases
  • # Of details
  • Perceptual, Semantic etc.
  • Vividness
  • Familiarity
  • This information increases the “feeling” that this imagined object or event was real
  • Source Monitoring Framework
  • Note: Reading information, answering questions etc. require some level of imagery

Eyewitness Suggestibility – Imagination Inflation

  • Research Examples
  • Punch Bowl (Loftus)
  • Lost in a shopping mall (Loftus)
  • Enemas (Pezdek, Blandon-Gitlin, Lam, Hart, & Schooler, 2006)
  • Pamphlets vs. guided imagery

Eyewitness Suggestibility –“Enema” Study

Eyewitness Suggestibility – Interrogation Wording

  • Traffic accident study – Speed (Loftus and Palmer, 1967)
  • Methods
  • Saw video of car accident
  • Asked to report speed of car
  • Manipulation: smashed, collided, bumped, hit or contacted

Eyewitness Suggestibility – Interrogation Wording

  • Traffic accident study – Speed * Results
  • Smashed: 40.8 miles an hour
  • Contacted: 31.8 miles an hour
  • Verb choice has biasing effects on participants’ report
  • Traffic accident study – Stop vs. Yield sign (Loftus and Hoffman, 1989)
  • Methods
  • Saw video of car accident
  • Completed questionnaire – manipulated suggested information
  • What was the color of the car that stopped at the “yield sign”?
  • Traffic accident study – Stop vs. Yield sign * Methods cont. * Delay
  • Final test
  • Report memory of the video clip, not questionnaire * e. “What was the sign”?
  • Results
  • Suggested information reduced accuracy
  • Recalled incorrect sign more often if exposed to yield sign misinformation
  • Difficulty differentiating event information from information learned after the event
  • Source monitoring error

Eyewitness Suggestibility Research

  • Method to reduce false memory and bias
  • Cognitive Interview (Fisher)
  • Used memory research findings to develop interview techniques for police

Eyewitness Suggestibility Summary

  • Factors leading to inaccurate EW testimony
  • Guided Imagery
  • Imagining an event* May lead to imagination inflation, reporting imagined event as “real”
  • Source monitoring explanation
  • Source monitoring error

Eyewitness Suggestibility Summary

  • Factors leading to inaccurate EW testimony * Interrogation Wording
  • May bias eyewitness reports
  • Interrogation Wording
  • False information, given during interrogation, may lead to false memory in eyewitness reports

Eyewitness Suggestibility Summary

  • Methods developed to reduce false memory and bias
  • Cognitive Interview

Eyewitness ID Research

  • Phenomena that affect eyewitness identification
  • High physiological arousal
  • Cross Race Effect
  • Lineup Procedure
  • Sequential/ Simultaneous/ Show up

Eyewitness ID Research: Physiological Arousal

  • Survival school training (Morgan, et al. 2004)
  • Subjected to conditions similar to P.O.W.s
  • Food and sleep deprivation for 48 hours followed by interrogation
  • Methods
  • Two instructors – “guard” and “interrogator”
  • Each person received a High (physical) and Low stress interrogation
  • 24 hours later, asked to identify their interrogator and guard

Eyewitness ID Research: Physiological Arousal

Eyewitness ID Research: Cross Race Effects

  • Meissner – Cross Race Effects (CRE)
  • ID accuracy  when witness race ≠ perp race
  • Why
  • Encoding problem* Certain facial features are more diagnostic for some races then others
  • g. color (skin, hair, eye) vs. size (nose, mouth, eyes)

Eyewitness ID Research: Lineup Procedure

  • Previous Research
  • Show up VS Simultaneous VS Sequential
  • Show up- clearly worse lineup procedure

Eyewitness ID Research: Lineup Procedure

  • Simultaneous VS Sequential * Previous research – Wells, Lindsay etc. * Sequential Lineup Advantage
  • Eliminates identifications based on “best match”* Current research – Gronlund, Lane, Clark etc.
  • Sequential Lineup – Conservative Shift
  • Simultaneous Lineup – Liberal Shift

Eyewitness ID Summary

  • Factors that affect identification accuracy
  • Physiological arousal (Stress)
  • Survival school
  • Stress led to decreases in correct identifications
  • Despite 1) interrogations lasted 30 minutes or longer,

2) nothing and no one else in the room 3) constant interaction

Eyewitness ID Summary

  • Factors that affect identification accuracy
  • Cross Race Effect (CRE)
  • Accuracy decreases when witness and perpetrators races do not match
  • Encoding problem
  • Consider “Penny study”

Eyewitness ID Summary

  • Factors that affect identification accuracy
  • Lineup Procedure
  • Show up – worst identification/ most inaccuracies
  • Simultaneous and Sequential – Differ in willingness to “choose”