Psychology in Court
Chapter 14
A Brief History
 Cattell
(1895)
 Questions
about everyday observations and
the nature of testimony
 Binet
(1900)
 Suggestibility
 Stern
 The
in children
(1910)
eyewitness ‘reality experiment’
Psychologists in Court

Von Schrenck-Notzing (1896)
 First
forensic psychologist in literal form
 German expert witness in serial sexual
murder case
 Extensive pre-trial press coverage
 Retroactive memory falsification
 What was seen versus what was heard
Forensic Psychology in North America
 Munsterberg

(1908)
On the Witness Stand
 Psychology and the legal system
 Resistance from legal scholars
 Pushed psychology into legal arena
 Father of forensic psychology
Forensic Psychology in North America
 Legal
cases in U.S. address admissibility of
‘expert testimony’
 Influence of Jenkins v. United States
(1962)
 Dealt
with whether psychologists should be
allowed to provide expert testimony on issues of
mental illness
 U.S. Supreme Court decided that some
psychologists are qualified to provide such
testimony
U.S. Decisions Regulate Scientific Expertise
 Frye
v. United States
 Standard
of general acceptance of scientific principle
or discovery
 Daubert
 Set
v. Merrell Dow Pharmaceuticals
out new rules to consider in evaluating novel
scientific evidence
 Emphasis on the validity of the science behind the
testimony
 Experts should back up what they say by citing and
explaining relevant findings
 Big problems for psychology and psychiatry
Admissibility of Expert Testimony
 Daubert
Criteria
 Be
provided by a qualified person
 Be relevant
 Be reliable
 Peer
reviewed
 Testable
 Recognized rate of error
 Meet professional standards
Seeking to Introduce “novel” expert
evidence




Father accused of sexually assaulting his two
children
Defense attempted to introduce a psychiatrist
who would give the opinion that the accused did
not possess deviant personality traits
Based his opinion on a PPG
Judge excluded evidence (no standard profile
established; necessity & relevance criteria not
met)
WHY????????????




Court found technique generally recognized by
scientific community as a therapeutic tool but
first time as a forensic tool (novel purpose)
Closeness of opinion to issue – if evidence
accepted, it would exclude accused from group
of potential offenders
Relevant & necessary – tests not reliable nor
applicable (<50% dectected)
Cost benefit – evidence offered as many
problems as it did solutions
ANOTHER EXAMPLE

Quantitative analysis of QEEG
 Novel
scientific technique not established as
reliable
 Not meeting threshold test of reliability
WHAT HAPPENED?
Expert had international reputation
 Published articles
 Opinion previously accepted by another
Alberta trial judge in 1998
 BUT: expert didn’t know if anyone else in
Canada used QEEGs
 No scientific standard existed – different
computer programs & techniques
 Rejected evidence on reliability factor

Scientific and Specialized Witnesses
 Expert
witness: unbiased, not an advocate
 Two primary functions:
Provide an opinion
2. Educator to judge and jury
1.
 What
qualifies a person as an expert
witness?

Training
 Experience

Testimony must be deemed RELIABLE and
Topics for Psychologists as
Expert Witness
Sentencing and rehabilitation
 Eyewitness identification
 Child custody
 Social issues (spouse abuse)
 Psychological evaluations

Roles of the Psychologist
Clinical
Role
 Assessment
 Unbiased
 Prediction
of offenders
reports
and reduction of future
dangerousness
 Interventions designed to rehabilitate criminal
offenders
 Working with police and victims
Roles of the Psychologist
 Experimental
Role
 Most
often based in social, personality,
cognitive or developmental areas
 Jury
decision making
 Eyewitness identification
 Impact of expert witness
 Role of children in the courtroom
Roles of the Psychologist
 Advisory
Role
 Advising
lawyers about psychological
evidence of other experts
 “destructive” role
Roles of the Psychologist
 Actuarial
Role
 Applying
statistical probabilities to behaviours
and events
Psychology and Criminal Law
 Pre-trial
 Fitness
& NCRMD (mostly a psychiatrist’s domain)
 Trial
 Actus
reus (the guilty act)
 Mens rea (intent to commit the act)
 Pre-sentence
 Mitigation
 Treatment
 Risk
assessment