Transcript P300 in Detection of Deception

When will the P300-CTP be
admissible in U.S. Courts?
J.Peter Rosenfeld & John
Meixner
Northwestern University.
Admissibility issues:
 Any scientific expert testimony offered by a party
in either a civil or criminal case must be
evaluated by the judge as to its reliability.
 in all federal courts and in the majority of state
courts,3 the judge assesses reliability under the
Daubert standard, derived from the United States
Supreme Court’s opinion in Daubert v. Merrell
Dow Pharmaceuticals (1993).
Daubert Standard: 4
criteria:
(1) “whether [the theory or technique]
can be (and has been) tested,”
 (2) “whether the theory or technique has
been subjected to peer review or
publication,”
 (3) “the known or potential rate of
error,” (in the field---the rub.)
(4) the “general acceptance” of the
technique
Frye Standard
In a minority of state courts, a different
(and much simpler) standard is followed,
derived from the nearly 100-year-old case
Frye v. United States (1923). Under the
Frye standard, any scientific evidence that
is to be admissible “must be sufficiently
established to have gained general
acceptance in the particular field in
which it belongs” (Frye, 1923). (Like
Daubert #4)
A second kind of standard…
Any testimony that solely assesses the
credibility of other witnesses competes
with the role of the jury, which has
been given the role of determining the
credibility of the witnesses.
a court might rule inadmissible a
polygraph expert whose testimony
essentially amounts to a statement that
one of the other witnesses was or was not
lying.
For example…
This view was espoused in the United
States Supreme Court’s most recent
polygraph decision, United States v.
Scheffer (2003), in which the Court barred
a defendant’s attempt to admit ANS
polygraph-based control question test
evidence indicating that he was truthful.
Thus….
The principal opinion, written by Justice
Clarence Thomas, focused on
“[p]reserving the court members’ core
function of making credibility
determinations in criminal trials,” (p. 312–
313) stating plainly that “the jury is the lie
detector.” (p. 313).
Regardless of whether the
standard is a good one…..
Thus, the way the CIT is represented to
judges will determine whether it is ruled
inadmissible as impinging on the role of
the jury.
While the CQT and its variants are truly
credibility assessment tests in that they
make claims about whether the tested
individual was truthful or deceptive, the
CIT makes no such claim.
Instead-. The CIT provides substantive evidence
of whether an individual recognizes
information that is relevant to the legal
question at hand, and leaves the
credibility assessment itself to the jury.
While this information may undermine the
credibility of a witness indirectly, it is no
different than any other piece of evidence
offered at trial, such as the presence of a
fingerprint that may undermine the
defendant’s denial of guilt.
OK, we can do that…
…and the main remaining problem is
determining error rate in the field, which
involves a test on real detainees. This
leads to a Catch 22:
IRBs essentially forbid work on prisoners,
who are considered a vulnerable
consideration. Thus no grants.