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 which states:
• 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, and/or testable.
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 operation.
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.