Chapter 8: Expert Psychological Testimony Flashcards
What kind of witnesses are there in expert psychological testimony?
- Fact witness and Expert witness
What are the functions of an expert witness?
- Aid in understanding a particular issue relevant to the case
- Qualification - Provide an opinion
What is a fact witness?
- direct knowledge about the facts of something. Saw, heard, and observed.
What is an expert witness?
- it is different in that you can give an opinion. Thoughts and opinion on diagnose. Children suggestions. Inform the court about your evaluation on a subject you are fluent in.
- not common knowledge
What does qualification have to do with expert witness???
Court has to be convinced you are the credentials; CV and you’re training to be allowed present as an expert witness.
however, being qualified does not mean you give a good opinion.
What is the common issue for which a psychologist may provide an opinion?? FCSETCPCCPS
- fitness to stand trial
- Criminal Responsibility
- Sentencing
- Eye witness identification
- Trial Procedure
- Civil commitment/Guardianship & Conservatorship
- Psychological damages in civil cases
- Class action suites
- Child Custody/Adoption/Termination of parental rights
- Professional malpractice
- Social issues in litigation
What is the percentage experts are used in the U.S.?
95%/4 experts per trial
What are the challenges of providing expert testimony?
Ethical issues:
- Providing non-partisan opinions
- Not an advocate or decision-maker
- Avoid working only for “one-side” across cases
- Being careful not to go beyond psychological science to offer an opinion.
What is necessary in expert testimony?
- you need to make sure that you are advising the court, do not offer the opinion that they wanted, you need to only offer their facts. Time it took to have an opinion not paying me to have your opinion that is best need for you defense or prosecution.
What are the differences that exist between the fields of psychology and law?
- eyewitness memory
- research not sufficient - challenged by the Sophonow 2001 inquiry
- Judges assume that the information to be reported by the expert is common-knowledge of the average juror
- Fear a “battle of the experts”
What is “Battle of the experts?”
not an expert so how is you supposed to weigh the information when you do not know or understand what they are saying.
What are the dangers of Junk Science & Errors in opinion formation?
Junk Science
- Poorly controlled research
- Biased samples, insufficient samples
- Failure in replication - easier to find things wrong if it is replicated
- Inappropriate statistical methods, etc.
- analysis something inappropriately
What is the challenge of distinguishing incompetence from deliberate deception/misrepresentation of evidence to justify one’s opinion?
- difficult to accuse someone of lying because it is still their opinion.
- minimize evidence - only talk about evidence that supports their bias
- telling they have more credentials than they do
- go beyond the limits of scientific data
- Errors in miscalculating something.
What is the solution to resolving the dilemma between the limits of science and experts opinion??
Saks (1992) identified three ways that an expert might resolve this dilemma:
- The conduit-educator
- The philosopher rules/advocate
- The hired gun
- the latter two approached contradict Canadian Psychological Association Ethical Guidelines –> do not misrepresent the research or present it in an unbalanced manner.
What is the conduit-educator method?
This is someone who is an expert in their own field, and that is it. My first duty is to show the most accurate knowledge in this area. not trying to be considered of moral or ethical standards. To tell the whole truth. Strengths and weaknesses. Everything that is relevant.
What are the philosopher rules/advocate method?
They take an oath to tell the whole truth is less important than the first one. Only tells research that is asked of them. Omit anything that might challenge what is not their sides.
What is the hired gun method?
Refer to experts that have paid opinions. Favors one’s side position. Whoever is paying them they say exactly what is needed.
What is the admissibility of expert testimony in North America - Expert quality?
Expert testimony must be based on reliable and valid research evidence. - Replicable findings, sound research methodology, falsifiable premises, etc.
What has legislators developed for specific legal criteria for establishing whether the science of the experts meets this standard - in Canada?
- Kelliher (village of) v. Smith (1931) - beyond “ordinary” people
- R v. Mohan (1994) - necessary & relevant
- law makers have developed safeguards that they think helps not allow junk science from getting into the courtroom.
- has to base upon reliable evidence.
- credibility is irrelevant in the courtroom when expert witnesses are involved only the findings in which this expert has come to with the knowledge given.
What is the effect of psychological expert testimony - is the expert psychological testimony necessary??
YES - Many areas that the judiciary have assumed are within the “common sense” knowledge of most triers of fact have been discounted by research.
E.g., errors and influences on eyewitness memory, the validity of children’s testimony, and the ability to detect deception.
Does Expert testimony influence jurors’ decisions?
YES - e.g., Schuller and Hastings (1996)
- Expert evidence linked directly to the trial evidence is more influential than expert evidence providing with an implicit like to trial evidence.
- Evidence based on clinical judgment is more influential than actuarial-based judgments.
- Qualitative comparison descriptions by experts are more influential than quantitative comparisons. Examples to help you understand what I am saying. Data driven loses people.
Is expert testimony on psychological topics appropriate??
Depends on:
- validity of assessment & diagnostic measures.
- validity of the application of group-based psychological instruments of making predictions in individual cases (e.g., risk of re-offending estimates, suitability for employment)
- Generalizability of laboratory-based research to the real-world context
Is psychological expert testimony objective?
- not always
- example: Murrie, Boccaccini, Johnson, and Janke (2008)
- experts hired by defense or court who both administered the psychopathy checklist-revised
- found allegiance effect in PCL-R scores
What is Adversarial Allegiance?
The tendency for forensic evaluators to form opinions in a manner that better supports the party that retains them.
Is unreliable expert testimony admitted?
- probably
- Groscup et al. (2002): analyzed 700 cases to determine how U.S. judges applied the Daubert criteria
- Most gave greater scrutiny to expert testimony in their decisions, but were just as likely to admit expert testimony as they were before the Daubert criteria rule
- Gatowski et al (2001)
- most judges in a U.S. national survey felt they lacked the scientific training necessary to fulfill their gate keeping role, and 5% or fewer judges clearly understood key terms such as falsifiability and error rate.
Are jurors sensitive to variations in the reliability of expert testimony?
sort of - McAuliff, Kovera, and Nunez (2009)
sensitive to missing control groups, but not to confounds or experimenter bias
- cross-examination, instruction to juries about the burden of proof, and the presentation of contrary evidence outlined as safeguards to assist jurors in their examination of expert evidence do not seem to have the desired impact.
