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McNally v. State, 980 A.2d 364 (Del. 2009)

Case (cite)
McNally v. State, 980 A.2d 364 (Del. 2009)
Type of proceeding
Type of claim
Type of claim (second claim)
Expert evidence ruling reversing or affirming on appeal:
What was the ruling?
Correct to Admit
Type of evidence at issue:
Firearms identification
Defense or Prosecution Expert
Name of expert(s) who were the subject of the ruling
Carl Rone
Summary of reasons for ruling
the firearms examiner's inability to recall how he arrived at a conclusion that certain shell castings had similar markings did not render admission of his expert testimony plain error because (1) he explained the principles and methods that he uses when testing casings for identifiable markings (2) the law requires the principle and methods - not the conclusions to be scientifically valid.Thus, we cannot find plain error because Rone did explain his principles and methodology and applied those principles and methods to the facts. McNally was able to cross examine Rone on those principles and his methodology. McNally was also able to expose Rone's lack of recollection about the application of the methodology to the facts here.
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


compare this case with Willock