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United States v. Johnson, 2015 WL 5012949 (N.D. Cal. 2015)

Case (cite)
United States v. Johnson, 2015 WL 5012949 (N.D. Cal. 2015)
Type of proceeding
Type of claim
Expert evidence ruling reversing or affirming on appeal:
What was the ruling?
Other; Trial court
Type of evidence at issue:
Firearms identification
Defense or Prosecution Expert
Name of expert(s) who were the subject of the ruling
Tasha Smith
Summary of reasons for ruling
The court holds that the AFTE theory satsifies all Daubert factors. The court mostly relies on the analysis of other courts. The court also holds that the defendants failed to raise a novel challenge to the accepted AFTE methodology and therefore was not entitled to an evidentiary hearing. Finally, the court holds that the methodology was reliably applied in this case because she did not state the match was to 100% certainty and was only to "sufficient agreement," and the expert adequately documented her findings and the basis for her conclusions by following industry standards.
The jurisdiction’s standard for expert admissibility at the time – list all that apply: (Frye), (Daubert), (Post-2000 Rule 702), (Other)
702; Daubert
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) or PCAST report (PCAST)
Discussion of error rates / reliability
Frye Ruling
Limiting testimony ruling
N (but see notes)
Language imposed by court to limit testimony
Ruling based in prior precedent / judicial notice
Daubert ruling emphasizing – which factors – (list 1-5)
(1); (2); (3); (4); (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


“This Court will not require Smith to qualify her expert opinion with the rigid disclaimer that the match is “more likely than not,” as such a specific restriction seems arbitrary. However, should Smith testify at trial that the items matched with “absolute certainty,” or to some other arbitrary degree of statistical certainty, the Court will take the necessary steps to strike such improper testimony immediately.”