Armitage, S, Saywell, S, Roux, C, Lennard, C & Greenwood, P 2001, 'The Analysis of Forensic Samples Using Laser Micro-Pyrolysis Gas Chromatography Mass Spectrometry', Journal of Forensic Sciences, vol. 46, no. 5, pp. 1043-1052.
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Abstract Laser micropyrolysis gas chromatography-mass spectrometry is used for the analysis of paint, photocopier toner, and synthetic fiber materials to test the forensic potential of this emerging technology. It uses a laser microprobe to selectively target very small parts of the materials for GC-MS analysis. Whereas the paint and the toner samples were amenable to direct laser pyrolysis, the synthetic fibers proved transparent to the 1064 nm laser radiation. The difficulty with the fibers demonstrates that a specific laser wavelength may not be appropriate for all types of materials. Nevertheless, the fibers were able to be indirectly pyrolyzed by impregnation in a strongly absorbing graphite matrix. A vast array of hydrocarbon pyrolysates was detected from the different materials studied. Unique product distributions were detected from each sample and in sufficient detail to facilitate individual molecular characterization (i.e., molecular fingerprinting). The integrity of the laser data were confirmed by comparison to data obtained from the same samples by the more conventional pyroprobe pyrolysis GC-MS method. The high spatial resolution and selectivity of the laser method may be advantageous for specific forensic applications, however, further work may be required to improve the reproducibility of the data.
Cantrell, S, Roux, C, Maynard, P & Robertson, J 2001, 'A textile fibre survey as an aid to the interpretation of fibre evidence in the Sydney region', Forensic Science International, vol. 123, no. 1, pp. 48-53.
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Frequency figures of the fibre population on textile cinema seats were measured in Sydney, Australia, in winter. Sixteen seats were analysed from a very popular cinema complex, with 3025 fibres classified according to colour, generic class and fluorescence properties (100 grey-black cotton fibres only). The recovered fibres were mostly natural fibres (84%) with cotton the most common generic type (70%). On the contrary, man made fibres were relatively rare (15%) with rayon constituting the majority of these (51%). The most common colour/generic class combinations were grey-black cotton (33%) and blue cotton (30%) accounting for 63% of the total population. All other frequencies were below 5%, most below 1% using only the two properties of colour and generic class. Fluorescence properties were found to be very discriminating as far as grey-black cotton fibres were concerned. These features are considered and discussed and in particular, to emphasise the significance of fibres as evidence of contact. © 2001 Elsevier Science Ireland Ltd. All rights reserved.
Conn, C, Ramsay, G, Roux, C & Lennard, C 2001, 'The effect of metal salt treatment on the photoluminescence of DFO-treated fingerprints', FORENSIC SCIENCE INTERNATIONAL, vol. 116, no. 2-3, pp. 117-123.
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Ninhydrin developed ®ngerprints can be enhanced by treatment with a zinc or cadmium salt. The resulting ®ngerprint luminescence has been attributed to the induced coplanarity of the bicyclic indanedione rings of Ruhemann's purple due to complexation with the metal ions. This paper explores whether this effect also occurs in the 1,8-diaza-9-¯uorenone (DFO)- amino acid adduct (1), formed from the reaction of DFO with amino acids. Molecular modeling studies of (1) indicate a relatively small out-of-plane angle of 248. 1H NMR studies indicate (1) is asymmetric about the C2 axis in contrast to what has been previously reported. Little, if any, enhancement of luminescence was observed with Zn, Cd, Ru or Eu treated DFO developed latent ®ngerprints. This lack of enhancement was also borne out by solution luminescence studies. Given this lack of enhancement of luminescence, solutions of (1) and the four metal ions above were analyzed by electrospray mass spectrometry (ESMS). This indicated the formation of predominantly 1:1 complexes of (1) with both Zn and Cd, and the 2:1 complex with ruthenium. No evidence of a Eu complex was found by ESMS.
Jones, N, Mansour, D, Stoilovic, M, Lennard, C & Roux, C 2001, 'The influence of polymer type, print donor and age on the quality of fingerprints developed on plastic substrates using vacuum metal deposition', Forensic Science International, vol. 124, no. 2-3, pp. 167-177.
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This study investigated fingerprint development on five different polymer substrates using vacuum metal deposition (VMD). The conditions required for optimum development are shown to depend on a number of factors. No one set of conditions will result in good development in all situations. Polymer type has been confirmed as a major factor in determining the types of development that will occur and the optimum VMD conditions required. For more consistently successful VMD development, polymer type should be determined before selecting conditions. While polymer type is a key factor in determining optimum development conditions, there may be variation of the optimum conditions within a polymer type, most likely due to the presence of additives in the plastic. The heaviness of a latent print, i.e. amount of residue that constitutes the print, also affects the VMD conditions required. The donor, manner of deposition, and age of a print affect the heaviness of the deposit. The heavier the print, the higher the gold count necessary for successful VMD development. The occurrence of empty prints (i.e. zinc deposition on the general background but not on or between the print ridges) was found to be related to polymer type and print heaviness. Heavy prints on PVC and PET are the most likely to be empty after VMD treatment. The development of empty prints may be due to the diffusion of print residue into the print valleys. Pre-treatment with cyanoacrylate fuming was also found to affect VMD development. In particular, it was shown that cyanoacrylate pre-treatment was beneficial for print development on PET and PVC. The results of this study were used to formulate guidelines for use as an aid by laboratories using VMD in casework.
Jones, N, Stoilovic, M, Lennard, C & Roux, C 2001, 'Vacuum metal deposition: developing latent fingerprints on polyethylene substrates after the deposition of excess gold', Forensic Science International, vol. 123, no. 1, pp. 5-12.
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Jones, N, Stoilovic, M, Lennard, C & Roux, C 2001, 'Vacuum metal deposition: factors affecting normal and reverse development of latent fingerprints on polyethylene substrates', Forensic Science International, vol. 115, no. 1-2, pp. 73-88.
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Vacuum metal deposition (VMD) is an established technique for the development of latent fingerprints on non-porous surfaces. VMD has advantages over cyanoacrylate fuming, especially in circumstances where prints are old, have been exposed to adverse environmental conditions, or are present on semi-porous surfaces. Under normal circumstances, VMD produces `negative prints as zinc deposits onto the background substrate and not the print ridges themselves. A phenomenon of `reverse development, when zinc deposits onto the print ridges and not the background, has been reported by many authors but its causes have not been conclusively identified. Four plastic substrates were used in this study and these could be easily divided into two groups based on the types of development observed as the amount of deposited gold was increased. On group I plastics, identified as low-density polyethylene (LDPE), normal development then reverse development and finally no development resulted with increasing gold. On group II plastics, identified as high-density polyethylene (HDPE), normal development then over-development and finally poor-quality normal development resulted with increasing gold. Our results suggest that the difference between these plastic types causes variations in the gold film structure which in turn dictates the nature of the zinc deposition. On group I plastics, the structure and thickness of the gold film has been identified as the critical factor in the occurrence of normal or reverse development. Thin gold films on plastic substrates form small `clusters (or agglomerates) rather than the atoms being uniformly spread over the surface. The size and shape of these clusters is critical. Once the clusters reach a certain morphology, they no longer act as nucleation sites for zinc, and hence, zinc will not deposit onto the substrate.
Maynard, P, Allwell, K, Roux, C, Dawson, M & Royds, D 2001, 'A protocol for the forensic analysis of condom and personal lubricants found in sexual assault cases', Forensic Science International, vol. 124, no. 2-3, pp. 140-156.
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Maynard, P, Gates, K, Roux, C & Lennard, C 2001, 'Adhesive Tape Analysis: Establishing the Evidential Value of Specific Techniques', Journal of Forensic Sciences, vol. 46, no. 2, pp. 280-287.
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Abstract This study investigated the evidential value of specific methods of analysis for packaging tapes and clear adhesive tapes available in Australia. Fifty-eight adhesive tapes were analyzed using a wide range of optical, physical, and chemical techniques. The results were collated for the purpose of creating an Australian database of adhesive tapes, which would be of assistance in criminal investigation. Each technique was evaluated for its discriminating power, both for comparative purposes and for the identification of adhesive tapes by comparing unknown samples with the database. The combined discriminating power of the techniques applied is very high. It is possible to individually identify the source of an unknown adhesive tape sample in many instances by searching the database. It is also possible to form an opinion on the significance of a failure-to-discriminate result in comparative casework. Further work is still needed to expand and update the database, as well as compiling data on the relative market share of various products.
Mitchell, C & McNevin, D 2001, 'Alternative analysis of BOD removal in subsurface flow constructed wetlands employing Monod kinetics', WATER RESEARCH, vol. 35, no. 5, pp. 1295-1303.
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A new, mechanistic approach for design and analysis of subsurface flow (SSF) constructed wetlands is presented. The model is based on the assumption that the biological processes in wetlands, like other biological systems, exhibit Monod kinetics. A Monod approach fits well with observed wetland performance. It predicts first-order behaviour at low concentrations, that is, pollutant removal rates which increase with increasing pollutant concentration; and zero-order or saturated behaviour at high pollutant concentrations, that is, a maximum pollutant removal rate. A kinetic analysis of subsurface flow constructed wetlands exhibiting Monod kinetics reveals that loading rate, as well as the zero-order degradation rate constant, are essential parameters for efficient wetlands design for the removal of organic carbon. In particular, Monod kinetics enables the identification of an absolute maximum removal rate which is necessary to prevent undersizing in design. This is significant because it represents a theoretical upper bound on loading rate for wetlands design. The analysis is applied to wetlands data collected in North America by the US EPA in order to extract design criteria for BOD removal. It reveals that maximum loadings for SSF wetlands are at least 80kgha-1d-1 for BOD. In addition, a new dimensionless performance efficiency parameter, Ω, is presented as a more effective means of comparing wetland performance. Copyright © 2001 Elsevier Science Ltd.
Roux, C, Huttunen, J, Rampling, K & Robertson, J 2001, 'Factors affecting the potential for fibre contamination in purpose-designed forensic search rooms', Science & Justice, vol. 41, no. 3, pp. 135-144.
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This study investigated fibre movement within and out of a search room, when performing a garment examination. The effect of the collection procedure (taping v. scraping) on the number of contaminant fibres produced, and the effectiveness of a number of cleaning techniques and varying degrees of examiner hygiene were also studied. Fibre movement was found to be dependent upon distance, with fibre populations decreasing with increasing distance from the garment examination area. Most fibres were deposited during the actual examination. Cotton fibres were more easily shed and also found to be airborne for longer periods of time than wool, acrylic and polyester fibres. The ‘scraping method’ of fibre recovery was found to result in an increase in the number of loose fibres with transfer to the examiner’s clothing and a number of fibres exiting the search room. It is unlikely that a completely clean search room can be obtained. However, with proper precautions it is possible to minimise and monitor the contaminant fibre population. These features are presented and discussed in this paper. © 2001 Forensic Science Society.
Roux, C, Kirk, R, Benson, S, Van Haren, T & Petterd, CI 2001, 'Glass particles in footwear of members of the public in south-eastern Australia — a survey', Forensic Science International, vol. 116, no. 2-3, pp. 149-156.
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A total of 776 pairs of shoes collected from random members of the public in south-eastern Australia were examined for the presence of glass fragments. From the samples collected a total of 110 fragments were recovered from 57 pairs of shoes (7.3% of the pairs examined). This study shows that the prevalence of glass fragments in footwear is dependent upon the area of the shoe from which the fragments were recovered. A much higher percentage of shoes were found to have fragments embedded in the sole (5.9%) than in the upper area of the shoe (1.9%). These shoes were also more likely to have multiple fragments from multiple sources of glass. Only a very small percentage of shoes contained fragments in both the upper and the sole (0.3%). These ®ndings and their signi®cance for the interpretation of glass evidence involving footwear are discussed in this study.
