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Sexton v. State, 93 S.W.3d 96 (Tex. Crim. App. 2002)

Case (cite)
Sexton v. State, 93 S.W.3d 96 (Tex. Crim. App. 2002)
Year
2002
State
Texas
Type of proceeding
Appellate
Type of claim
Evidentiary
Expert evidence ruling reversing or affirming on appeal:
Excluded
What was the ruling?
Remand
Type of evidence at issue:
Firearms identification
Defense or Prosecution Expert
Prosecution
Name of expert(s) who were the subject of the ruling
Ronald Crumley
Summary of reasons for ruling
The court found that, although toolmark theory was widely accepted, the literature on did not discuss its effectiveness in cases where only magazine marks were used. The court disagreed with the expert's assetion that the technique used was 100% accurate and noted that the magazine that made the marks in this case was never found so the expert could not make comparison marks and did not say whether he was familiar with the manufacturing process. Finally, the evidence establishing the expert's expertise did not "support his capacity to identify cartridge cases on the basis of magazine marks only." "We conclude, based on the record before us, that the underlying theory of toolmark examination could be reliable in a given case, but that the State failed to produce evidence of the reliability of the technique used in this case. Under the Kelly criteria, the State failed to show that the technique applied in this case was valid."
The jurisdiction’s standard for expert admissibility at the time – list all that apply: (Frye), (Daubert), (Post-2000 Rule 702), (Other)
702; Kelly ((1) the extent to which the underlying scientific theory and technique are accepted as valid by the relevant scientific community, if such community can be ascertained, (2) the existence of literature supporting or rejecting the underlying scientific theory and technique, (3) the clarity with which the underlying scientific theory and technique can be explained to the court, (4) the potential rate of error of the technique, (5) the availability of other experts to test and evaluate the technique, (6) the qualifications of the expert(s) testifying, and (7) the experience and skill of the person(s) who applied the technique on the occasion in question.)
Did lower court hold a hearing
Y
Names of prosecution expert(s) two testified at hearing
Crumley
Names of defense expert(s) who testified at hearing (or None).
N/A
Discussion of 2009 NAS Report (NAS2009) or PCAST report (PCAST)
N
Discussion of error rates / reliability
Y
Frye Ruling
N
Limiting testimony ruling
N
Language imposed by court to limit testimony
N/A
Ruling based in prior precedent / judicial notice
N
Daubert ruling emphasizing – which factors – (list 1-5)
Court used Texas' version of Daubert that includes 7 factors: (1) the extent to which the underlying scientific theory and technique are accepted as valid by the relevant scientific community, if such community can be ascertained, (2) the existence of literature supporting or rejecting the underlying scientific theory and technique, (3) the clarity with which the underlying scientific theory and technique can be explained to the court, (4) the potential rate of error of the technique, (5) the availability of other experts to test and evaluate the technique, (6) the qualifications of the expert(s) testifying, and (7) the experience and skill of the person(s) who applied the technique on the occasion in question
Ruling on qualifications of expert
Y
Ruling on 702(a) – the expert will help / assist the jury
N
Ruling on 702(b) – the testimony is based on sufficient facts or data
N
Ruling on 702(c) – the testimony is the product of reliable principles and methods
Y
Ruling on 702(d) – reliable application of principles and methods to the facts of the case
Y

Notes

These references may support the general theory of using toolmarks for connecting cartridges generally, but it does not support the particular application in this case.

 

This record qualifies Crumley as a firearms identification expert, but does not support his capacity to identify cartridge cases on the basis of magazine marks only.