Nothing in the text of this Rule establishes “general acceptance” as an absolute prerequisite to admissibility.
US courts began formalizing standards for admissibility of scientific evidence in 1923. James Alphonzo Frye, charged with the murder of his physician, tried to present a systolic blood pressure deception test as evidence. The psychologist who examined Frye claimed that the results of this test demonstrated that Frye had been honest in his denial of guilt. The initial court that heard the case and then later the District of Columbia Court of Appeals agreed that the test and its results were not admissible as scientific evidence:
“We think the systolic blood pressure deception test has not yet gained such standing and scientific recognition among physiological and psychological authorities as would justify the court in admitting expert testimony deduced from the discovery, development, and experiments thus far made.”
The admissibility of scientific evidence took a turn beginning in 1972 with the development of the Federal Rules of Evidence (FRE) and parallel state rules of evidence. The new standard allowed an expert who was qualified by “knowledge, skill, experience, training or education” to testify, if the testimony constituted, or was based upon, “scientific, technical, or other specialized knowledge.”
Then in 1993, these admissibility rules were clarified through a landmark opinion, Daubert v. Merrell Dow Pharmaceuticals, Inc. (a civil case involving a study on the effects of an anti-nausea drug and its asserted link to birth defects). The Court suggested a non-exclusive list of guidelines for use by trial courts in determining admissibility—expanding the focus from general acceptance to more measurable determinants.
Today states vary in which standard they use and some use mixed standards or have established their own, focusing on reliability. There are states that have adopted standards referred to as “relevancy” or “reliability” guidelines for trial courts, directing trial judges to examine several factors when ruling on admission of novel scientific evidence, including:
Academics frequently refer to the Supreme Court’s decision in Daubert as a landmark change in the approach to the admissibility of scientific evidence. Many practitioners disagree. In jurisdictions that currently or previously had used the Frye general acceptance standard, contested hearings often include testimony or other evidence addressing:
Each of these areas is a proper subject of inquiry for a witness offering an opinion that a test or technique is generally accepted in the scientific community.
Just when a scientific principle or discovery crosses the line between the experimental and demonstrable stages is difficult to define. At some point the evidential force of the principle must be recognized. While courts will go a long way in admitting expert 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 to which it belongs.