Challenging the reliability of expert testimony.

• Jurisdiction: United States
• Date: 01 July 2001
• Author: Bittick, E. Kelly, Jr.

Since 1993, a series of cases from the U.S. Supreme Court has firmly established reliability as the key to the admission of expert testimony in federal court and affirmatively charged trial courts with minding the gates of evidence. The Supreme Court of Florida, however, has declined the opportunity to align Florida's expert testimony requirements with their recently adopted federal counterparts. Instead, Florida continues to adhere to the former federal standard--a standard focusing on the general acceptance of the principles and discoveries underlying an expert's opinions.

Florida's persistent focus on the general acceptance standard should not be taken to mean that reliability is not relevant to the admissibility of expert testimony under Florida law. To the contrary, reliability is a highly pertinent inquiry when examining all expert testimony.

The Federal Standards from Frye to Daubert

For many decades, the dominant standard for the admission of new and novel expert evidence was that set forth in Frye v. United States, 293 F. 1013 (D.C. Cir. 1923). Under the Frye test, which was announced long before the federal courts adopted an evidence code, a "scientific principle or discovery" that forms the basis for an expert's deductions "must be sufficiently established to have gained general acceptance in the particular field in which it belongs."(1) This remained the leading standard until the U.S. Supreme Court discarded it in 1993 in favor of a more broad reliability examination.

In Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579, 585 (1993), the Court held that Fed. R. Evid. 702 requires only that expert scientific evidence be reliable and that a valid scientific connection link that evidence to the facts of a given case. Daubert offered a nonexclusive list of factors to consider when evaluating reliability, including whether the principle or technique has been or can be tested, whether it has been subjected to publication and peer review, whether there is a known or potential error rate, and, as under Frye, whether the principle or technique is generally accepted in the scientific community.(2) The Court also held that Rule 702 compels trial judges to act as "gatekeepers" with regard to all expert testimony, allowing only reliable, relevant evidence to enter the courtroom.

Florida's Adherence to Frye for Ensuring Reliability

As did the federal courts, Florida first embraced the general acceptance test of Frye long before the adoption of an evidence code.(3) The Supreme Court of Florida relied on Frye as early as 1953, when the court decided that the improper admission of evidence concerning a lie detector test warranted a new trial.(4) Thereafter, the court revisited the issue of the polygraph's admissibility and, while stressing that the reliability of scientific tests and experiments must be shown in order to admit evidence based solely on them, held that the evidence in the case failed to show that the polygraph had gained "such reliability and scientific recognition as to warrant its admissibility."(5)

After Florida adopted its evidence code, which, like its federal counterpart, contained no express requirement that scientific principles or theories be generally accepted to be admissible in court, a number of Florida's intermediate appellate courts questioned whether the Frye standard continued to apply to opinions based on new and novel science.(6) The Florida Supreme Court appeared to answer in the affirmative in Stokes v. State, 548 So. 2d 188, 195 (Fla. 1989). There, the court rejected the case-by-case use of a balancing test to weigh the probative value of scientific evidence against the dangers of unfair prejudice. Stokes adopted instead Frye's general acceptance standard, explaining that courtrooms are not laboratories in which to conduct experiments. Stokes expressly held that "[i]f the scientific community considers a procedure or process unreliable for its own purposes, then the procedure must be considered less reliable for courtroom use."(7)

Stokes did not directly address the admissibility of expert testimony, but whatever doubt existed regarding the applicability of Frye to expert testimony in Florida was put to rest in the post-Daubert case of Flanagan v. State, 625 So. 2d 827, 828 (Fla. 1993). While noting the federal courts' movement under Daubert, Flanagan squarely held that expert testimony based on novel scientific evidence is not admissible in Florida unless it meets Frye's test of general acceptance.

Through a number of subsequent decisions, the Florida Supreme Court has reaffirmed the applicability of the Frye test and expanded on its proper implementation at both the trial and appellate court levels. Hadden v. State, 690 So. 2d 573, 580 (Fla. 1997), held that a Frye examination is only necessary where the party against whom expert scientific testimony is offered challenges the reliability of that evidence.(8) Thus, Florida's trial courts are not charged with exercising gatekeeping functions sua sponte.

Ramirez v. State, 651 So. 2d 1164, 1167 (Fla. 1995), held that a decision on the admission of novel scientific opinion evidence consists of multiple steps. These include determining whether such testimony will help the jury understand the evidence or determine a fact in issue and deciding whether the expert's testimony is based on a scientific principle or discovery that is sufficiently accepted so as to have gained general acceptance in the relevant field. These are matters to be decided by the trial court.(9)

Ramirez further held that the determination of whether a principle or discovery is generally accepted by the relevant scientific community is made through an adversarial proceeding, with the burden on the proponent of the evidence to establish general acceptance by a preponderance of the evidence.(10) The court need not accept an expert's "bald assertion" that a particular principle or discovery is generally accepted.(11)

In Brim v. State, 695 So. 2d 268, 272 (Fla. 1997) (Brim I), the Florida Supreme Court clarified that, to determine general acceptance of the science underlying an expert opinion, the trial court must conclude that a clear majority of the members of the relevant scientific community supports each of the underlying principles or techniques. Mere numerical majority support or opposition of persons minimally qualified to state an authoritative opinion is not alone dispositive, since in determining the general acceptance issue, trial courts must consider "the quality, as well as the quantity, of the evidence supporting or opposing a new scientific technique."(12)

Finally, Brim I and Hadden make clear that a Frye determination is a question of law that is reviewed de novo on appeal.(13) Appellate review should consider the issue of general acceptance as of the time of the appeal, rather than the time of the trial court's determination, and the appellate court is encouraged to examine expert testimony, scientific and legal writings, and judicial opinions.(14) Florida appellate decisions therefore provide instructive guides for trial courts to follow when analyzing the admissibility of evidence subject to Frye.

Applicability of Frye Under Florida Law

Under Florida law, Frye is not applicable to all expert testimony. One area carved out by the Supreme Court as not falling within the ambit of Frye is so-called "pure opinion testimony." Such testimony is based on a person's experience and training, rather than scientific principles or tests.(15) As the Supreme Court explained in Flanagan, "this testimony is analyzed by the jury as it analyzes any other personal opinion or factual testimony by a witness."(16) A court must be vigilant, however, to assure itself that testimony claimed to be based purely on "personal" experience is in fact so derived.(17) To the extent an expert has utilized scientific principles, studies, or tests to reach an opinion, then, to admit that opinion, those principles, studies, and tests must survive a Frye analysis.(18)

A second, albeit related, area to which courts hold Frye inapplicable is nonscientific methodology or reasoning. Thus, in Williams v. State, 710 So. 2d...