As new techniques and technologies emerge that will purportedly help judges and juries resolve various legal issues, courts must determine whether testimony based on these new approaches is sufficiently reliable to permit them to be introduced into evidence.
For seventy years, from 1923 to 1993, the federal courts largely relied on a test articulated in Frye v. United States, 293 F. 1013 (D.C. Cir. 1923), that focused on whether the method, theory, or technology in question had "gained general acceptance in the particular field in which it belongs." This case focused on an early prototype of the polygraph, called the systolic blood pressure deception test, which had been promoted at the time as one of several types of "cutting-edge" lie-detection technologies. The court in Frye determined that the test had not yet been "generally accepted" in the scientific community and refused to admit test results into evidence.
The United States Supreme Court in Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993), augmented Frye with a number of other factors that federal courts are to consider in determining whether such information is sufficiently reliable to be admitted into evidence. These factors include (1) whether the underlying science of the proposed evidence has been or can be tested, (2) whether the scientific theory or technique has been subjected to peer review, (3) whether accuracy rates for the proposed evidence are known, and (4) whether the theory or technique had gained general acceptance by the relevant scientific community (the Frye test).
Daubert, however, is only binding on the federal courts, with each state free to adopt its own rules regarding the admissibility of what is asserted to be scientific information into evidence. Virginia is one state that has not embraced fully either Frye or Daubert and has adopted its own approach. The Virginia Supreme Court pronounced the following rule governing the admissibility of scientific evidence in Spencer v. Commonwealth, 240 Va. 78, 97, 393 S.E.2d 609, 621 (1990):
When scientific evidence is offered, the
court must make a threshold finding of fact
with respect to the reliability of the
scientific method offered, unless it is of a
kind so familiar and accepted as to require
no foundation to establish the fundamental
reliability of the system, such as fingerprint
analysis; or unless it is so unreliable that
the considerations requiring its exclusion
have ripened into rules of law, such as "lie-detector"
tests; or unless its admission is
regulated by statute, such as blood-alcohol
In a case of first impression before the Virginia Supreme Court, the court was asked to address the admissibility at a sentencing proceeding of testimony based upon plethysmograph testing. The defendant in the case, a juvenile at the time, had been charged with forcible sodomy of a child under the age of 13. After being transferred out of juvenile court and tried as an adult, the defendant was found guilty. The trial court then ordered a presentence report containing a psychosexual evaluation pursuant to Virginia Code [section] 19. …