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Williams v. United States, 210 A.3d 734 (D.C. 2019)

Case (cite)
Williams v. United States, 210 A.3d 734 (D.C. 2019)
District of Columbia
Type of proceeding
Type of claim
Type of claim (second claim)
Expert evidence ruling reversing or affirming on appeal:
What was the ruling?
No Error due to Harmless Error
Type of evidence at issue:
Firearms identification
Defense or Prosecution Expert
Name of expert(s) who were the subject of the ruling
Summary of reasons for ruling
The appellate court agreed with Defendant that the trial court should not have permitted the unqualified testimony definitively matching the murder weapon to the gun found in Defendant's apartment. This decision is controlled by Gardner, 140 A.3d 1172 (D.C. 2016).
The jurisdiction’s standard for expert admissibility at the time – list all that apply: (Frye), (Daubert), (Post-2000 Rule 702), (Other)
Second standard
Rule 702
Did lower court hold a hearing
Names of prosecution expert(s) two testified at hearing
Names of defense expert(s) who testified at hearing (or None).
Discussion of 2009 NAS Report (NAS2009)
Discussion of 2016 PCAST report (PCAST)
Discussion of error rates / reliability
Frye Ruling
Limiting testimony ruling
Language imposed by court to limit testimony
Ruling based in prior precedent / judicial notice
Daubert ruling emphasizing – which factors – (list 1-5)
(3); (5)
Ruling on qualifications of expert
Ruling on 702(a) – the expert will help / assist the jury
Ruling on 702(b) – the testimony is based on sufficient facts or data
Ruling on 702(c) – the testimony is the product of reliable principles and methods
Ruling on 702(d) – reliable application of principles and methods to the facts of the case


1. When asked was there “any doubt in [his] mind” that the gun found in defendant’s bedroom was the murder weapon, the testifying expert replied “[n]o, sir.” Then he restated his unequivocal opinion several times. (“Those markings are unique to that gun and that gun only.”) (“Item Number 58 fired these three bullets.”). 2. Gardner is still the controlling precedent on admissibility of unqualified firearms identification testimony even though it was decided under Frye rule. 3. The court admitted here that the Gardner footnote 19 poses some level of ambiguity saying that its holding still allows “toolmark experts to offer an opinion that a bullet or shell casing was fired by a particular firearm” provided that they do not do so with “absolute or 100% certainty.” But this ambiguity does not affect the current case because here the expert’s affirmative language is even stronger than in Gardner.




Following Gardner, we repeat that it is error to allow an examiner to provide this kind of unqualified opinion testimony, but we do not foreclose the possibility that the necessary data will exist at some point in the future to provide a foundation for opinion testimony that unqualifiedly connects a specific bullet to a specific gun. Rather, we conclude only that we do not have such a foundation in this case.


“Our endorsement in Motorola of a test for the admission of expert testimony that focuses on reliability dovetails perfectly with the analysis in Gardner. Although decided when Frye/Dyas was still the law, Gardner scrutinized the firearms and toolmark examiner’s opinion testimony through a reliability lens and cited sources that explain that the empirical foundation does not currently exist to permit these examiners to opine with certainty that a specific bullet can be matched to a specific gun. In line with Motorola, Gardner determined that these conclusions are simply unreliable.
Although, in the government’s view, Motorola should have no effect on this appeal, it expresses concern that this court, applying our en banc decision, might hold that all firearms and toolmark evidence is inadmissible. We do not so hold, and we do not question the admissibility of the firearms and toolmark examiner’s testimony generally.”