The congressional enactment of the Federal Rules of Evidence (FRE) led to confusion about the applicability and survival of the Frye standard. These rules govern the admissibility of all evidence in federal courts including scientific evidence. The FRE ask whether a person is qualified to testify and whether the proffered testimony assist the trier of fact in understanding the evidence or determining the facts at issue. Many were concerned that the FRE 702 were more liberal that the Frye standard and that the FRE 702 did not distinguish between what is or is not scientific testimony. Many states decided to remain faithful to the Frye standard because it was already codified in their state law or because of the general confusion on whether the FRE actually superceded Frye.
FRE 702 (eff. Dec. 1, 2011) courtesy of Legal Information Institute at Cornell University Law School