Transcript Scientific Evidence - Hastings College of the Law

Scientific Evidence
Scientific Evidence (cont.)
► Evid.
Code § 801 – includes reasonable reliance
standard
► People
v. Kelly (1976) 17 Cal.3d 24
 California adopts the Frye v. U.S. “general acceptance”
test: the proponent must persuade the judge that the
novel scientific or technique has been sufficiently
established to have gained general acceptance in the
particular field in which it belongs.
 General acceptance, not just reasonable reliance, is the
test.
Scientific Evidence (cont.)
Kelly-Frye rule:
This test promotes a degree of uniformity with respect to the admissibility
of evidence based on scientific principles
Protects against individual bias by judges against a technique where they
are presented with general acceptance in the relevant community
Protects the trial process from the unrestrained admission of evidence
based on new and untested scientific principles
Responds to concerns of a misleading aura of scientific infallibility
attached to techniques that are experimental or dubious validity
e.g. truth serum, polygraphs, penile plethsmographs, human bite marks
Scientific Evidence (cont.)
Kelly-Frye rule:
not limited to scientific techniques, can also
apply to novel social science research
- e.g. a new technique based on
psychology such as hypnotically
refreshed memory
Scientific Evidence (cont.)
► Kelly-Frye
rule:
► Once a technique has been shown to be
generally accepted, and that finding is
affirmed on appeal in a published decision,
the technique does not have to pass muster
under the Kelly-Frye test unless the
opponent can show that the view in the
scientific community has changed
Scientific Evidence (cont.)
► Kelly-Frye
rule:
► Evid. Code § 405 hearing
► Must convince judge of 3 things:
 1) evidence would assist trier of fact
 2) technique is generally accepted in the
relevant discipline
 3) procedures, protocols and methodologies
were properly followed
Scientific Evidence (cont.)
► Kelly-Frye
rule:
► Re: general acceptance prong
 1) court should weigh the qualifications of the experts
testifying about general acceptance
 2) court should hesitate before accepting the testimony
of a single expert on this issue
 3) court should avoid giving too much weight to experts
that have too much interest in the general acceptance
 4) court may consider decisions from other jurisdictions
and may independently review relevant scientific
literature
Scientific Evidence (cont.)
► Daubert
► Federal
v. Merrill Dow Pharmaceuticals
509 U.S. 579 (1993)
Rules of Evidence overrule common
law Frye rule (general acceptance test)
Scientific Evidence (cont.)
► Daubert:
 That the Rules displace the Frye test does not
mean that the Rules themselves place no limits
on the admissibility of purportedly scientific
evidence
 To the contrary, the Rules require the trial
judge to ensure that any and all scientific
evidence is not only relevant, but also reliable
Scientific Evidence (cont.)
► Daubert:
 FRE 402 (relevant evidence is admissible and
evidence which is not relevant is inadmissible)
provides the baseline
 FRE 702, which governs expert testimony,
controls:
►Nothing
in this Rule establishes “general acceptance”
as an absolute prerequisite to admissibility
FRE 702 - Expert Opinion
► Applies
to scientific, technical or other
specialized knowledge
► Must assist the trier of fact
 In understanding the evidence
 In determining a fact in issue
► Must
be an expert by reason of knowledge,
skill, experience, training or education
FRE 702 - Expert Opinion
► May
testify to opinion or otherwise, if
 1) the testimony is based on sufficient facts or
data;
 2) the testimony is the product of reliable
principles or methods;
 3) the witness has applied the principles and
methods reliably to the facts of the case
Scientific Evidence (cont.)
► Daubert:
 FRE 702 requires that for expert testimony to
be admissible, it must assist the trier of fact in
understanding the evidence or in determining a
factual issue
 This condition is a relevance requirement
Scientific Evidence (cont.)
► Daubert:
 When faced with a proffer of scientific evidence,
the trial judge must, pursuant to FRE 104
(preliminary question determination), determine
whether
►1)
the expert is proposing to testify to scientific
knowledge; and
►2) that such testimony will assist the trier of fact
Scientific Evidence (cont.)
► Daubert:
 Flexible inquiry under Rule 702
 Non-exclusive list of factors of which the trial court
should inquire:
► Whether
the theory or technique can be, or has been, tested
► Whether the theory or technique has been subjected to peer
review and publication
► What known or potential error rate is of the theory or technique
► Whether the theory or technique is generally accepted within
the relevant scientific community
Scientific Evidence (cont.)
Kelly-Frye rule:
► People v. Leahy (1994) 8 Cal.4th 587
 Rejects Daubert approach and retains Kelly-Frye
test in California