Examination of Firearms Review: 2007 to 2010 - Interpol

the nature of the garment in question being drawn. The need for caution in its
application and an appreciation of the factors affecting the technology are
emphasised in intelligence led casework.
7. Analysis
Due to the prevailing economic climate, now more than ever purchase of new
instrumentation and adoption of new methods of analysis are dependent upon
demonstrable improvements in time, resources and/ or increased
discrimination before uptake is justified in terms of cost. Nevertheless, over
the past three years research in this area has continued.
Biermann [34] carried out a study to determine the variation in blue and red
cotton fibres using light and fluorescence microscopy, UV/Vis
microspectrophotometry with particular attention being paid to the recurrence
of certain spectral patterns. The importance of spectral information in the UV
range is re-emphasised, as is the importance of colour in the forensic
comparison of cotton fibres. The author demonstrated that the combination of
tests employed can give a high power of discrimination, (DP c. 0.98)
enhancing the evidential value of red and blue cotton fibres in fibre transfer
cases.
Similar results were obtained in a study of non-denim blue cotton fibres by
Palmer et al [35] to determine the degree of discrimination obtained between
non-denim blue cotton fibres using visible-UV range MSP alone. The
discriminating power of visible range MSP was calculated to be 0.89 for 'midblue'
garments and 0.87 for 'dark blue' garments. Extending MSP into the UV
range increased discrimination by 7%, giving a discriminating power of 0.96
for both mid and dark blue cotton fibres, which was similar to that reported by
Biermann [34]. The implications of this study for casework are discussed and
a revised analytical pathway for the comparison of this fibre type/colour
combination using MSP as a primary screening tool is proposed.
Research into the application of Raman spectroscopy to the forensic
examination of textile fibres has continued since the last review, with
members of the European Fibre Group being the most active in this area [36-
38]. Despite this research, adoption of this technique into the majority of
operational laboratories is still poor, possibly because it has still to
demonstrate substantial advantages over the combination of existing
techniques and in many respects has been shown to be complimentary;
Massonett and Buzzini [36] compared Raman spectroscopy against
microscopy, UV-Vis MSP and TLC in the discrimination of acrylic, cotton and
wool fibres. The results of their study showed that in the majority of cases
microscopy and UV Vis MSP provided the greatest discrimination and that the
optimal analytical sequence varies with the fibre type/ colour combination
(according to the discrimination power).
Coyle et al [37] investigated the use of Raman spectroscopy in the subclassification
of cellulosic fibres. Whilst it was possible to distinguish the
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