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U.S. v. Johnson, 2019 WL 1130258 (S.D.N.Y. 2019)

Case (cite)
U.S. v. Johnson, 2019 WL 1130258 (S.D.N.Y. 2019)
New York
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
Jonathan Fox
Summary of reasons for ruling
Defendant argued that testimony should be excluded because toolmark identification is too subjective, there is no known arror rate, and there is no empirical basis that individual firearms leave unique marks. The court held that all Daubert factors were satisfied, largely supporting their reasoning through cases from other jurisdictions. Further the court stated, "the weaknesses in the methodology of toolmark identification analysis are readily apparent, have been discussed at length in the scientific literature, and can be addressed effectively on cross-examination. These weaknesses are also not particularly complicated or difficult to grasp, and thus are likely to be understood by jurors if addressed on cross-examination" Because the expert clearly stated that he "would never" state his conclusions as 100% certainty, the court declined to limit his testimony.
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)
All factors
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


Although this Court is aware of no decision that has outright excluded toolmark identification evidence as unreliable, over the past fifteen years the methodology for toolmark identification has come under increasing scrutiny in the courts.




It is also worth noting that the authors of the three scientific reports explicitly acknowledged that the rigorous, entirely objective, infallible, and certain standards that prevail within a scientific discipline are not necessarily properly applied in a courtroom. Indeed, the authors were careful to emphasize that their conclusions should not be read as commentary on the admissibility of toolmark evidence in courts.


Given the testimony at the Daubert hearing and the Government’s representations as to what it will elicit from Detective Fox, there is no need for this Court to impose limitations on Detective Fox’s opinions.