Testimony by Expert Witnesses

(a) If scientific, technical, or other specialized knowledge will assist the trier of fact to understand the evidence or to determine a fact in issue, a witness qualified as an expert by knowledge, skill, experience, training, or education may testify thereto in the form of an opinion or otherwise. (b) In addition to the requirements in subsection (a), expert testimony based on a novel scientific theory, principle, methodology, or procedure is admissible only if: (1) the testimony is based on sufficient facts or data; (2) the testimony is the product of reliable principles and methods; and (3) the expert has reliably applied the principles and methods to the facts of the case COMMENT ON RULE 702 Rule 702 is a modified version of its federal counterpart. The revised rule applies existing case law that requires expert testimony based upon novel scientific theories to be evaluated by the trial court exercising its "gatekeeper" function. See Syllabus point 2, Harris v. CSX Transportation, 232 W.Va. 617, 753 S.E.2d 275 (2013).