Expert Opinion Testimony After Porter: Connecticut Adopts the Daubert Standard
| Publication year | 2021 |
| Pages | 346 |
71 CBJ 346. Expert Opinion Testimony After Porter: Connecticut Adopts the Daubert Standard
On May 20, 1997, the Connecticut Supreme Court issued its long-awaited decision in State v. Porter (fn1) Abandoning the Attorney general acceptance" standard for the admissibility of scientific evidence first enunciated in Frye v. United States, (fn2) Connecticut became the latest jurisdiction to determine, based upon the United States Supreme Court's holding in Daubert v. Merrell Dow Pharmaceuticals, Inc., (fn3) that such evidence may be admitted only if it is derived by application of a sound scientific method.
By adopting the Daubert standard, the Connecticut Supreme Court greatly enlarged the role of the trial judge. The rule of Porter is that the trial judge may no longer simply satisfy himself that the expert's opinion is "generally accepted" and, therefore, admissible. Instead, he must now scrutinize how the expert arrived at his conclusion and, in his role as a judicial "gatekeeper," (fn4) exclude those opinions which are not premised upon "good science." (fn5)
Porter's adoption of Daubert creates valuable opportunities for lawyers who seek to admit expert opinions that, although out of the mainstream, can be shown to be based upon a demonstrably scientific technique. If the opinion is grounded in the methods and procedures of science, the mere fact that it is novel or unique is no longer sufficient to exclude it. By permitting a wider range of opinions, Daubert can thus be considered to have liberalized the rules controlling the admissibility of expert testimony. (fn6)
At the same time, however, Daubert stresses that the trial judge must focus on the reliability of the testimony. After Daubert, even an opinion that is "generally accepted" could theoretically be excluded if it could be shown to be premised
on a poor scientific method. By focusing attention on the scientist's methods and by articulating some of the ways that they can be critically evaluated, Daubert can also, therefore, be viewed as tightening the standards against which such evidence is judged.
This article is intended to provide the reader with a brief history of Daubert, to then examine its holding in greater detail, and, finally, to discuss the application of its principles in a practical context.
In Frye, the defendant, on trial for murder, took and supposedly passed a lie detector test. When the defendant sought to introduce the examiner's opinion about the reliability of such tests, the testimony was excluded and the defendant was convicted. On appeal, the circuit court affirmed the conviction, holding that expert testimony was admissible only if the opinion was one considered by scientists to be "generally accepted." (fn7) In other words, the opinion had to be excluded unless it could be characterized as one that was agreed to "by a substantial section of the scientific community." (fn8)
The "general acceptance" standard of Frye governed the admissibility of expert testimony in the federal courts until 1993, when the United States Supreme Court decided Daubert. In Daubert, the plaintiffs sought to establish a link between serious birth defects and a mother's prenatal ingestion of Bendectin. The trial court granted summary judgment in favor of the defendant manufacturer because the plaintiffs could not establish that their expert's causation opinion was "generally accepted" as required by Frye. (fn9) The Court of Appeals affirmed, again relying on Frye. (fn10)
On appeal, the Supreme Court reversed. The court noted that Federal Rule of Evidence 702 (fn11) does not require
that an expert's opinion be "generally accepted" as a prerequisite to its admissibility. (fn12) Focusing on the language of Rule 702, the court instead found that the testimony should be admitted if it (a) constitutes "scientific knowledge"; and (b) "assist[s] the trier-of-fact to understand the evidence or to determine a fact in issue." (fn13)
By abandoning Frye's "general acceptance" standard, Daubert recognizes that an opinion may still be worthy of consideration even though it is not wholeheartedly embraced by the scientific community. Instead, if the opinion can be shown to result from a deliberative thought process based upon the scientific method, and if it will help the trier of fact understand matters at issue in the case, it meets the threshold requirements for admissibility. (fn14)
At its most basic level, Daubert calls upon the court to concern itself with the scientist's analytical technique, not the merits of his opinion. (fn15) In this respect, Daubert stands in stark contrast to Frye. Under Frye's "general acceptance" test, the court focused on the opinion itself, not the manner by which it was arrived at, and if the opinion was widely held it was, absent some other reason for its exclusion, usually admitted. (fn16)
Daubert recognized these shortcomings in the Frye standard. Under Daubert, the court is called upon to engage in a two-step analysis. First, it must determine if the proposed tes
timony constitutes "scientific knowledge." (fn17) In this regard, Daubert notes that "[t]he adjective 'scientific' implies a grounding in the methods and the procedures of science." (fn18) Daubert, therefore, requires that the expert's opinion be derived through application of the scientific method - "subjecting testable hypotheses to the crucible of experiment in an effort to disprove them." (fn19) Examining the term "knowledge," Daubert similarly observed that "knowledge" can be said to "appl[y] to any body of known facts or to any body of ideas inferred from such facts or accepted as truths on good grounds." (fn20) Subjective beliefs, unsupported conclusions, and conjecture do not constitute "knowledge." (fn21) Thus, taken together, Rule 702's reference to "scientific knowledge" requires that the testimony be derived from a deliberative thought process applied to facts or observations obtained through application of scientific procedures. Daubert observed that Rule 702 sought to establish a standard of evidentiary reliability when it referred to "scientific knowledge." (fn22) To establish "reliability," the trier is called upon to examine whether the scientific principle truly supports what it purports to show. (fn23) In other words, the scientist's technique "must be supported by appropriate validation -i.e., 'good grounds,' based on what is known." (fn24) While recognizing that many factors may have a role in establishing that the opinion has "good grounds," Daubert suggested that courts consider the following:
A. whether the theory or technique has been or can be tested; (fn25)
B. whether the theory or technique has been subjected to peer preview and publication; (fn26)
C. the known or potential rate of error for the technique, including the existence and maintenance of standards
controlling the technique's operation; (fn27) and
D. whether the technique is, in fact, generally accepted in the scientific community. (fn28)
In applying these standards, the trial...
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