Must a Trial Judge Act as a Gatekeeper Even if Not Asked to Do So?

Here’s a question that arose during a recent class: Suppose that a party in a criminal case seeks to introduce forensic evidence from a discipline of questionable validity, such as bite mark analysis. The lawyer on the other side isn’t aware that the technique has been the subject of scientific criticism and doesn’t object. Must the trial judge nonetheless assess the reliability of the proposed testimony before admitting it? Although courts nationally don’t agree, I think the better answer in North Carolina is yes. This post explains why. Rule 702. The starting point for questions about expert witness is G.S. 8C-702, or evidence Rule 702. It provides that an expert witness may testify if the testimony is based upon sufficient facts or data, the testimony is “the product of reliable principles and methods,” and the witness has applied those methods “reliably to the facts of the case.” The rule effectively mirrors the holding of Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993), where the Supreme Court ruled that, under the federal evidence rules, “the trial judge must ensure that any and all scientific testimony or evidence admitted is not only relevant, but reliable” in light of several factors enumerated by the Court. Daubert hearings. Judges often implement Rule 702 by conducting hearings regarding the reliability of proposed expert testimony. These hearings are called “Daubert hearings,” and they fulfil what is commonly described as the “gatekeeping” function of the trial judge. See, e.g., Kumho Tire Co. v. Carmichael, 526 U.S. [...]