Frye Motion Law & Legal Definition


The term Frye motion comes from the case, Frye v. united States (D.C.Cir. 1923), a case discussing the admissibility of polygraph test as evidence.

A motion that is raised before or during trial, to exclude the presentation of unqualified evidence to the jury. This special type of motion in limine, is usually used to preclude or exclude scientific evidence that is not the result of a theory that has “general acceptance” in the scientific community.

The Frye test sets forth an exclusionary rule of evidence that applies only when a party wishes to introduce novel scientific evidence obtained from the conclusions of an expert scientific witness. Under Frye, a party wishing to introduce such evidence must demonstrate to the trial court that the relevant scientific community has reached general acceptance of the principles and methodology employed by the expert witness before the trial court will allow the expert witness to testify regarding his/her conclusions. However, the conclusions reached by the expert witness need not be generally accepted. Thus, a court's inquiry into whether a particular scientific process is generally accepted is an effort to ensure that the result of the scientific process, i.e., the proffered evidence, stems from scientific research which has been conducted in a fashion that is generally recognized as being sound, and is not the fanciful creations of a renegade researcher.