When it comes to expert testimony, Kansas adheres to the Frye test which
says, "Just when a scientific principle or discovery crosses the
line between the experimental and demonstrable stages is difficult to
define. Somewhere in this twilight zone the evidential force of the principle
must be recognized, and while the courts will go a long way in admitting
experimental testimony deduced from a well-recognized scientific principle
or discovery, the thing from which the deduction is made
must be sufficiently established to have gained general acceptance in the particular field in which it belongs."
Rather than use the Frye test, many other States follow the Daubert standard
• Judge is gatekeeper: Under Rule 702, the task of "gatekeeping",
or assuring that scientific expert testimony truly proceeds from "scientific
knowledge", rests on the trial judge.
• Relevance and reliability: This requires the trial judge to ensure
that the expert's testimony is "relevant to the task at hand"
and that it rests "on a reliable foundation". Daubert v. Merrell
Dow Pharms., Inc., 509 U.S. 579, 584-587. Concerns about expert testimony
cannot be simply referred to the jury as a question of weight. Furthermore,
the admissibility of expert testimony is governed by Rule 104(a), not
Rule 104(b); thus, the Judge must find it more likely than not that the
expert's methods are reliable and reliably applied to the facts at hand.
• Scientific knowledge = scientific method/methodology: A conclusion
will qualify as scientific knowledge if the proponent can demonstrate
that it is the product of sound "scientific methodology" derived
from the scientific method.
• Factors relevant: The Court defined "scientific methodology"
as the process of formulating hypotheses and then conducting experiments
to prove or falsify the hypothesis, and provided a nondispositive, nonexclusive,
"flexible" set of "general observations" (i.e. not
a "test") that it considered relevant for establishing the "validity"
of scientific testimony:
1. Empirical testing: whether the theory or technique is falsifiable, refutable,
2. Whether it has been subjected to peer review and publication.
3. The known or potential error rate.
4. The existence and maintenance of standards and controls concerning its
The degree to which the theory and technique is generally accepted by a
relevant scientific community.
However, Kansas and several other states, use the Frye test. In 1992, Kansas
voiced the importance of the Frye test and the Supreme Court even reversed
a DUI conviction because the Frye Test was not utilized when the Court
allowed in evidence of the Horizontal Gaze Nystagmus. In State v. Witte
251 Kan. 313, 836 P.2d 1110 (1992), The Supreme Court held that HGN results
are scientific evidence, hence the foundation for admission of results
requires meeting the criteria of the Frye test.
This means several things. First, if you have been accused of drunk driving
in Kansas, the HGN test results likely won't be used against you.
And good DUI attorney will prevent the HGN results from coming into evidence,
unless the State has an expert witness to lay the proper foundation. Second,
Kansas follows the Frye Test and will require it in cases where scientific
evidence is used. For example, if you are suing someone in Kansas because
they injured you while
drunk driving and you want to bring in evidence that is scientific in nature, your
personal injury lawyer will be required to prove the scientific reliability through the Frye test.