Examination of Firearms Review: 2007 to 2010 - Interpol

supported a conclusion that the red paint on the shoes and the red paint applied
to one of the buildings for the purposes of defacing its surface contained the
same observed and measured characteristics.
Two articles were published by Zadora and coauthors that described ongoing
efforts to determine the significance of paint transfer evidence using likelihood
ratios. One study utilized data generated by FTIR analysis and the other
employed Py-GC/MS results. [142;143] Stable isotope analysis of white paints
was another application of likelihood ratios described by Farmer et al. In this
study, isotope ratio mass spectrometry (IRMS) was used to analyze 13 C, 18 O, and
2 H isotopic compositions originating from paint binders.[144]
Further discussion of significance assessments were reported in Science and
Justice in 2010 as abstracts of presentations given at the 5 th Triennial
Conference of the European Academy of Forensic Science held in Glasgow,
Scotland in September 2009.[145] A number of presentations addressed the
need to provide context to report conclusions. Use of Bayesian statistics,
likelihood ratios, and development of a unified ordinal scale to describe levels of
conclusions were presented.
As a final note to the discussion of significance, paint examiners routinely review
trade journals and consult with experts from the coatings industry in order to
guide critical thinking as to the probative value of an examination request or the
appropriate interpretation of analytical findings. In this regard, educating the
paint and coatings industry about forensic paint examinations can be as critical
as the reverse. To that end, Mike Eyring, formerly of the Arizona Department of
Public Safety, wrote a review of several forensic paint cases that highlight how
forensic paint examinations are conducted and how they can be used within the
context of criminal investigations.[146]
9. Studies regarding automotive finishes and refinishes
Research on the performance of coated galvanized steel was reported on by
Santos et al. in which waterborne and solvent borne basecoats were compared
on primed and pre-primed steel sheets in order to study effects on
adhesion.[147] In general, the waterborne finishes showed better adhesion
results over the solvent borne coatings. Not surprisingly, the use of primers also
promoted better adhesion. Other results included comparison of the differences
noted between electrogalvanized, hot dip galvanized, and galvannealed steel for
these adhesion tests.
Three papers were published during this review period that discussed analysis or
development of systems used in automotive refinishes. In the first, automotive
body fillers were characterized in order to better assess discrimination of these
materials in casework.[148] Thirty-three samples of body filler and spot putties
were analyzed using light microscopy, FTIR, SEM/EDS, and Py-GC. Overall, 19
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