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United States v. Willock, 696 F.Supp.2d 536 (D.Md. 2010)

Case (cite)
United States v. Willock, 696 F.Supp.2d 536 (D.Md. 2010)
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
Arnold Esposito
Summary of reasons for ruling
because every reported federal decision is in favor of admitting the ballistics testimony, the testimony should be admitted here. But because (1) in light of the recent academic studies challenge the technique's status as "science" (2) the government's failure to produce documents on the expert's qualifications, proficiency, and adherence to proper methods, while admissible, the testimony should be restricted completely and the expert cannot state his conclusions with any degree of certainty.
The jurisdiction’s standard for expert admissibility at the time – list all that apply: (Frye), (Daubert), (Post-2000 Rule 702), (Other)
Rule 702
Second standard
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)
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


“While … it may be debatable whether [firearms tool mark identification evidence] is ‘science,’ it clearly is technical or specialized.”




very important for the expert to produce documents constituting bases and reasons for his firearms toolmark identification because “the subjectivity of firearms toolmark identification methodology plaes a great degree of emphasis on the individual’s training and proficiency, and the AFTE methodology requires proper documentation by notes, sketches, and photographs that illustrate how the examiner reached his or her conclusion, so that other examiners may confirm that conclusion by reference to the supporting materials.”


while courts have permitted its admission, there is a substantial reliance on the ability of defense counsel to be able to challenge the identification at trial through effective cross-examination, or by offering defense expert to challenging it.


timing is also important “the production 17 days before trial of 239 pages of additional documents related to the expert’s testimony, and the production one week before trial of 26 additional pages is distainful of the defendant’s due process rights to a fair trial”


echoing the Monteiro court, “peer review and documentation are prerequisites to admissibility, and the examiner’s qualificationsare of utmost importance.” Which which the testimony cannot be admissible at trial.