Judge Spotlights PCAST Report

When the District of Columbia Court of Appeals (the District's "supreme court") overruled Frye v. United States and replaced the general acceptance standard for scientific evidence with one based on the Daubert line of cases, 1/ the court admonished trial judges to use "a delicate touch" in regulating the flow of expert testimony. 2/ One judge offered more guidance. Judge Catharine Friend Easterly penned a concurring opinion proposing that

trial courts will be called upon to scrutinize an array of forensic expert testimony under new, more scientifically demanding standards. As the opinion of the court states, “[t]here is no ‘grandfathering’ provision in Rule 702,” and, under the new rule we adopt, courts may not “reflexively admit expert testimony because it has become accustomed to doing so under the Dyas/Frye test. 3/

Daubert does not necessarily erect a more demanding standard than Frye. It leaves plenty of wiggle room for undiscriminating or lenient rulings. Moreover, under Frye, counsel can challenge scientific evidence that is generally accepted in the forensic-science community (predominantly forensic-science practitioners) but whose scientific foundations are seen as weak in the broader scientific community. Both Frye and Daubert enable -- indeed, both require -- courts to depart from reflexively admitting expert testimony just because they are accustomed to it. The legal difference between the two approaches is that Daubert creates the theoretical possibility of rejecting a method that is still clearly generally accepted but that a small minority of scientists has come to regard -- on the basis of sound (but not yet generally accepted) scientific arguments -- as unfounded. This is merely the flip side of evidence that is not yet generally accepted but that is scientifically sound. Frye keeps such evidence out; Daubert does not. In sum, the standards are formally different, but, as written, one is not more demanding than the other.

But regardless of whether Daubert is more demanding than what the Supreme Court called the "austere" standard of Frye, the remainder of Judge Easterly's opinion is worthy of general notice. The opinion urges the judiciary to heed the findings of the 2009 NRC Report on forensic science and the 2016 PCAST report on particular methods. It observes that

Fortunately, in assessing the admissibility of forensic expert testimony, courts will have the aid of landmark reports that examine the scientific underpinnings of certain forensic disciplines routinely admitted under Dyas/Frye, most prominently, the National Research Council's congressionally-mandated 2009 report Strengthening Forensic Science in the United States: A Path Forward, and the President's Council of Advisors on Science and Technology's (PCAST) 2016 report Forensic Science in the Criminal Courts: Ensuring Scientific Validity of Feature-Comparison Methods [hereinafter PCAST Report]. These reports provide information about best practices for scientific testing, an objective yardstick against which proffered forensic evidence can be measured, as well as critiques of particular types of forensic evidence. In addition, the PCAST Report contains recommendations for trial judges performing their gatekeeping role under Rule 702:

(A) When deciding the admissibility of [forensic] expert testimony, ... judges should take into account the appropriate scientific criteria for assessing scientific validity including: (i) foundational validity,  with respect to the requirement under Rule 702(c) that testimony is the product of reliable principles and methods; and (ii) validity as applied, with respect to [the] requirement under Rule 702(d) that an expert has reliably applied the principles and methods to the facts of the case.
(B) ... [J]udges, when permitting an expert to testify about a foundationally valid feature-comparison method, should ensure that testimony about the accuracy of the method and the probative value of proposed identifications is scientifically valid in that it is limited to what the empirical evidence supports. Statements suggesting or implying greater certainty are not scientifically valid and should not be permitted. In particular, courts should never permit scientifically indefensible claims such as: “zero,” “vanishingly small,” “essentially zero,” “negligible,” “minimal,” or “microscopic” error rates; “100 percent certainty” or proof “to a reasonable degree of scientific certainty;” identification “to the exclusion of all other sources;” or a chance of error so remote as to be a “practical impossibility.”

PCAST Report, supra, at 19; see also id. at 142–45; Gardner v. United States, 140 A.3d 1172, 1184 (D.C. 2016) (imposing limits on experts' statements of certainty). 4/

Notes

1. Motorola v. Murray, 147 A.3d 751 (D.C. 2016) (en banc); Frye Dies at Home at 93, June 30, 2017, http://for-sci-law.blogspot.com/2017/06/frye-dies-at-home-at-93.html.
2. 147 A.3d at 757.
3. Id. at 759 (emphasis added).
4. Id. at 759-60 (notes omitted).

Index to comments and cases on the PCAST report