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Graham Davies Legal Psychology Week 6 Expert Evidence on Eyewitness Testimony.

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Presentation on theme: "Graham Davies Legal Psychology Week 6 Expert Evidence on Eyewitness Testimony."— Presentation transcript:

1 Graham Davies Legal 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 expert’s 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 - children’s 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


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