Graham Davies Legal Psychology

1
Graham DaviesLegal Psychology

• Week 6
• Expert Evidence on Eyewitness Testimony

2
The Psychologist as Eyewitness Expert

• First recorded case 1896
• - Shrenck Notzing in Germany
• Most prevalent in the US
• - 450 trials in 25 States (Brigham, 1988)
• - 87 for the Defence (Kassin et al. 1989)
• Landmark Trials
• - Robert Buckhout and the Angela Davies case
  (1972)
• - Elizabeth Loftus vs. Lenore Terr in People
  vs. Franklin (1994)

3
Fluctuating Rules for Admission of Expert
Testimony thumbs down?

• The Frye rule
• - testimony to be based on information and
  data
• generally accepted in the experts field
• US vs. Amaral (1973)
• - rejects eyewitness expert
• - expert evidence must be beyond common
  knowledge
• of the jury
• - evidence must be more probative than
  prejudicial

4
Fluctuating Rules for Admission of Expert
Testimony thumbs up?

• Federal Rules of Evidence (1975)
• - does it assist the Court ?
• - is the testimony sufficiently reliable ?
• State of Arizona vs. Chapple (1983)
• - decision reversed because no expert allowed
• The Daubert Judgement (1993)
• - reliability and relevance of evidence
  critical
• - peer review and publication relevant
  criteria
• But the legal door still only half open

5
The Backlash McCloskey Egeth (1983)

• Goals of expert testimony
• to correct any misapprehensions of jurors
• to assist in distinguishing reliable from
• unreliable testimony
• Neither of these achieved
• jurors not given new or reliable information
• jurors are just made more sceptical without
  improving reliability
• Psychologists should stay out of the courts !

6
Do jurors over-believe eyewitness testimony ?

• Experts summarise state of knowledge
• - Estimator and system variables
• - reliance on experimental findings
• Questionnaire Studies (Deffenbacher Loftus,
  1982)
• - good grasp of cross-race ID biased parades
• - poor grasp of weapon focus confidence and
• accuracy
• - calibration issue (Wells, 1986)
• - Judges knowledge and attitudes (Wise
  Safer, 2004)
• Eyewitness discrediting effect (Loftus, 1974)
• - not always reliable (Sanders et al. 1983)

7
Are Jurors made over-sceptical toward eyewitness
testimony ?

• Experts reduce conviction rate (62 to 42)
• but no improvement in accuracy
• (Wells et al. 1980)
• But if experts focus on critical variables
  they do improve juror accuracy
• (Wells Wright, 1983)
• Didactic vs. Case-based testimony

8
Subsequent Research

• Much more research on critical variables
• - weapon focus meta-analysis (Stablay, 1992)
• More realistic field studies
• - cross-racial ID (Brigham et al. 1982)
• - unconscious transference (Read et al.
  1990)

9
General Acceptance ?

• An emerging consensus (Kassin et al. 2001)
• - 80 or more agreement by experts
• - system variables (e.g. line-up instructions
  mugshot bias)
• - estimator variables (e.g. post-event
  information,
• leading questions cross-race ID)
• Consensus statements
• - childrens suggestibility in interviewing
  (Ceci Bruck, 1995)
• - identification methods (Wells et al. 2001)

10
Eyewitness Testimony in the United
Kingdom Testimony of psychologists in court
- rarely permitted (R v. Turner, 1975) -
briefing (typically) the Defence through
reports Judge takes on educational role
- Turnbull directions (Devlin 1976)
Little signs of change - 1993 Royal
Commission on Criminal Justice - 2002 Auld
Committee Report - But psychologists appear
regularly in civil cases