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Surface soil samples from several localized areas were analyzed for pollen and compared using an ordination analysis. The aim was to objectively establish the forensic value of using soil samples to link people or objects to crime scenes. This was done by determining the degree to which pollen assemblages of surface soil samples from within the same localized area differ, and the degree to which the pollen assemblage of a surface soil sample from within a localized area differs from distant localized areas of similar vegetation type. Samples from within the same localized area (the control site) showed a high degree of similarity, suggesting that pollen assemblages of surface soil samples from within a localized area are homogeneous. Results also showed that localized areas of similar vegetation type, even within the same geographic region, have significantly different pollen assemblages.

Glass is one of the most common types of trace evidence found at crime scenes and on suspects. The elemental analysis of float glass has become increasingly important as the range in values of refractive index has substantially narrowed due to increased quality control in glass manufacture. The purpose of this research was to investigate the variation of elements in automotive float glass relevant to New Zealand for the purpose of classifying and discriminating samples. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) was used to analyse the elemental composition of 243 automotive glass samples. An intact side window (tempered pane) and an intact windscreen (laminated pane) were analysed to investigate the spatial trend of elements in automotive glass. Most elements displayed no spatial variation over the panes. Pb had the largest variation in the windscreen and was also found to have a large variation in the database. Most samples were able to be classified into the vehicles' country of origin using a multiclass classifier. However, this was not possible for all samples, due to the origin of glass differing from the origin of the vehicle in some cases. The elemental composition of Australian and Northern Hemisphere samples differed greatly making them easy to separate; however, there was little variation within the Australian samples, making it hard to discriminate between different samples. A three step method, which combined the use of elemental composition, DRI and RI, was used to discriminate database samples. The method distinguished 84% (172/204) of samples in the database. When Australian samples were removed from the analysis, the discrimination increased to 95% (148/156). The type II errors were reduced by using both elemental composition and RI measurement.

Polydimethylsiloxane (PDMS) is commonly used to lubricate condoms. The detection of PDMS on swabs from complainants can be used to support an allegation of sexual assault. Previous research has focused on establishing analytical techniques for detecting PDMS. This research examined the persistence of PDMS on the penis, in the vagina, in the mouth, and on skin. The longest PDMS detection times were 20 h on the penis, 35 h in the vagina, and 52 h on skin. PDMS was detected up to 4 h in the mouth if the participant did not eat or drink and up to 9 h if the participant slept. PDMS was not detected in the mouth after eating or drinking. The presence of biological fluids had no detrimental effect on the analysis. Aqueous extraction of swabs for DNA did not remove any significant amount of PDMS; hence, swab remains could be subsequently analyzed for PDMS.