Because of low persistence of GSR on the hands, in some cases it is also worth sampling the clothing of the suspect. In our daily work, the numbers of samples from hands or clothing submitted to our laboratory are more or less the same.
As part of an accreditation process following the ISO 17025 norm and in order to evaluate some analytical performances such as reproducibility and robustness of our sampling method on clothing, some tests related to collection efficiency as a function of fabric type were performed. To our knowledge, and somewhat surprisingly, nothing has been published on this specific topic relating to GSR.Some studies dealing with clothing concerned the persistence and transfer of fibres (notably summarized in [5]), hair[6], glass[7] and paint fragments [8] .Bull et al. [9] focused on the persistence of small particles (less than 100 um diameter), and in particular on the persistence of lighter flint particles-for which the morphology and size are to a certain extent the same than for GSR-on viscose and nylon material.