3.1 Forensic Intro Flashcards
Forensic psychology definition
the application of psychological knowledge and theories to all aspects of the criminal and civil justice systems, including the processes and the people
admissibility criteria
experts must satisfy judge that they have special knowledge above and beyond that of the average juror and that this expertise will assist jurors
functions of an expert witness
- aid in understanding a particular issue relevant to the case
- provide an opinion
history of forensic psychology
how do expert witnesses differ from regular witnesses
regular witnesses can only testify about what they have directly observed (no opinions, analysis)
challenges of providing expert testimony
- lack of ecological validity of psychological research (real-world application)
- psychologists may become advocates, lose objectivity
- psychology can intrude upon legitimate activities of legal system
- it’s all common sense (not helpful)
admissibility criteria england + wales
- experts not commonly used
- just because qualified doesn’t mean will be helpful, danger jury will think so - too much weight put on expert opinion
- psychologists/psychiatrists not needed unless mental illness
- all other psych knowledge seen common knowledge
- some relaxing of Turner ruling = more evidence on not mental illness
admissibility criteria: australia
aus, NZ constrained by turner ruling, esp common-knowledge
- expert evidence relating to eyewitness testimony regularly disallowed
- evidence act 1995 NSW = common knowledge rule abolished
fingerprints analysis
- fingerprint experts very accurate, not perfect
- used in court >100yrs but 1st study to objectively investigate accuracy 2011
- err on side of caution = free the guilty, but occasionally could false convict
facial mapping analysis
- techniques not standardised, inconsistent
- take measurements, note characteristics
- much incriminating evidence of unknown validity + reliability
hair analysis
- almost all FBI examiners have given flawed testimony
- hair, bite mark analysis NOT good - subjective, pattern-based, wrongful convictions on feature-comparison methods
history: earliest research into eyewitness memory
James Cattell 1895, asked people to recall things they witnessed in their everyday life (e.g. apple seeds point) - often inaccurate
history: misleading questions
alfred binet 1900, showed kids objects e.g. button, asked questions about object (what colour was the string holding it there, but there wasn’t any) –> misleading questions = poor accuracy
history: reality experiments
- von Liszt 1902, Stern 1910 conducted reality experiments w/ staged events –> student ‘shot’ professor, best recall = 26% errors on main details, proves eyewitness unreliable, inaccurate
history: first appearances of psych in courts
- varendonck 1911, called to be expert in murder young girl case
- staged event at school, tested memory for event
- concluded children’s memories inaccurate –> “what colour was the teacher’s beard?” “brown” <– doesn’t even have a beard