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U.S. v. Davis, 2019 WL 4306971 (W.D. Va. 2019)

Case (cite)
U.S. v. Davis, 2019 WL 4306971 (W.D. Va. 2019)
Type of proceeding
Type of claim
Type of claim (second claim)
Expert evidence ruling reversing or affirming on appeal:
What was the ruling?
Type of evidence at issue:
Firearms identification
Defense or Prosecution Expert
Name of expert(s) who were the subject of the ruling
Wendy Gibson, Courtney Etzelmiller, Scott McVeigh
Summary of reasons for ruling
The court reasoned that, despite not having a science or engineering background, each expert's training and experience was sufficient to qualify them as experts. The court held that testimony should be limited due to the subjective nature and inability to provide a concrete error rate."Given the subjectivity of the field and the lack of any established methodology, error rate, or statistical foundation for firearm identification experts' conclusions, the testimony of the government's proposed witnesses will not be admitted in full. Neither, however, is the court persuaded that the above discussed fallibilities of firearm identification rob the entirety of the experts' testimony of value. Rule 702 and Daubert set requirements that extend broadly to permit expert testimony beyond that which is purely scientific and empirically-based."
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
Wendy Gibson, Courtney Etzelmiller, Scott McVeigh
Names of defense expert(s) who testified at hearing (or None).
Did not name defense expert that testified
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)
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


“McVeigh, Gibson, and Etzelmiller MAY:
• Provide testimony explaining their examination procedure and describe the comparison micrographs accompanying the reports produced in discovery;
• Describe any similar characteristics in the toolmarks observed on examined cartridge cases;
• Based on these observations, render an opinion as to whether toolmarks on certain cartridge cases bear marks consistent with each other.
McVeigh, Gibson, and Etzelmiller MAY NOT:
• Opine that certain cartridge cases were fired by the same gun;
• Opine that a cartridge case is a “match” to other cartridge cases or firearms;
• Opine that toolmarks reflect a “signature” permitting the conclusion that certain cartridge cases may be traced to a single firearm; or
• Express confidence in their opinions to any specific level of certainty, including whether the examiners’ observations exclude other firearms or cartridge cases “to a level of practical impossibility.””




Concerns over the reliability of this testimony expressed in the NRC and PCAST reports and those reflected in a recent chorus of federal decisions lead the court to impose certain restrictions on the testimony of these toolmark examiners.