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Investigations into the application of carboxyl-functionalised silicon oxide nanoparticles doped with a ruthenium complex (RuBpy-doped CES-SiO 2 NPs) for latent fingermark development on non-porous surfaces were reported in previous studies. These studies suggested that an optimised NP-based method demonstrated advantages in fingermark selectivity and sensitivity. To continue the series of research into using RuBpy-doped CES-SiO 2 NPs for fingermark detection, the versatility and overall practicality of the optimised SiO 2 NP-based reagent for latent fingermark detection and enhancement was evaluated. When the optimised NP-based method was used in a repeated fashion (application of multiple NP treatment cycles), it was found that the overall fingermark detection quality increased across the evaluated fingermarks without a high risk of overdevelopment. The possibility of incorporating the optimised NP-based reagent for potential operational use (e.g., at crime scenes) was successfully demonstrated via spray application on three test surfaces (aluminium foil, transparent polypropylene film and green polyethylene film). It was also shown that further enhancement of "spray-detected" fingermarks was achievable via subsequent treatment using the NP-based reagent in a colloidal dispersion bath. Additionally, the compatibility of the optimised NP-based method with two-step cyanoacrylate fuming for latent fingermark detection was evaluated. It was concluded that the two techniques are not compatible for application in a fingermark detection sequence. While encouraging results were demonstrated in this study, further optimisation and comparison will be required before the multiple-treatment and spray-treatment approaches can be considered for operational implementation., Competing Interests: Conflict of interest statement The authors declare no conflicts of interest for this study., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Unlike other more established disciplines, a shared understanding and broad acceptance of the essence of forensic science, its purpose, and fundamental principles are still missing or mis-represented. This foundation has been overlooked, although recognised by many forensic science forefathers and seen as critical to this discipline's advancement. The Sydney Declaration attempts to revisit the essence of forensic science through its foundational basis, beyond organisations, technicalities or protocols. It comprises a definition of forensic science and seven fundamental principles that emphasise the pivotal role of the trace as a vestige, or remnant, of an investigated activity. The Sydney Declaration also discusses critical features framing the forensic scientist's work, such as context, time asymmetry, the continuum of uncertainties, broad scientific knowledge, ethics, critical thinking, and logical reasoning. It is argued that the proposed principles should underpin the practice of forensic science and guide education and research directions. Ultimately, they will benefit forensic science as a whole to be more relevant, effective and reliable., Competing Interests: Declarations of interest Claude Roux is President of the International Association of Forensic Sciences (IAFS). Chris Lennard, Alastair Ross and Claude Roux are members of the Scientific Committee for the 23rd Meeting of the International Association of Forensic Sciences to be held in conjunction with the 26th Symposium of the Australian and New Zealand Forensic Science Society, 20 – 24 November 2023, Sydney, Australia (IAFS 2023)., (Copyright © 2022 The Author(s). Published by Elsevier B.V. All rights reserved.)

This paper reports the synthesis of high-quality upconverting nanoparticles (UCNPs) - sodium yttrium tetrafluoride doped with ytterbium and erbium (NaYF 4 :Yb,Er) with a silica shell and capped with phenyl functional groups. The main goal of this research was to design tailor-made UCNPs for fingermark detection, to test and validate a nanoparticle-based detection technique and to compare their performance against a benchmark method to assess potential implementation in routine practice by law enforcement agencies. The water-based UCNPs solution was applied to natural fingermarks on a number of substrates. This is the first ever systematic comparative study between UCNPs and a benchmark fingermark detection technique - cyanoacrylate fuming (CAF) followed by luminescent dye staining. Fingermark detection effectiveness was studied by treating 300 latent fingermark specimens on aluminium foil, polyethylene, polypropylene and glass slides. It was concluded that, on average, CAF performed better across the substrates tested. Nevertheless, UCNPs can be advantageous for fingermark detection on multicoloured, patterned or luminescent substrates due to their unique optical properties. There are, however, shortfalls associated with their synthesis and use that need to be addressed before they can be considered for operational purposes., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Among the different types of nanoparticles (NPs) proposed for fingermark detection, silicon oxide nanoparticles (SiO 2 NPs) are arguably the most promising due to their unique characteristics. In this study, carboxyl-functionalised SiO 2 NPs doped with luminescent ruthenium complex-RuBpy-doped CES-SiO 2 NPs-were further studied to investigate their effectiveness for latent fingermark detection. A modified version of the functionalised SiO 2 NPs with a lower amount of surface functionalisation is proposed for improved fingermark detection effectiveness. A shaking incubator was also incorporated into the fingermark detection process to offer a more viable treatment approach in comparison to the previously published method. The shaking incubator offered a more robust application approach, as well as improved fingermark detection quality. To gain an insight into fingermark detection effectiveness relative to benchmark techniques, the performance of the optimised RuBpy-doped CES-SiO 2 NPs was compared to that of a benchmark fingermark detection method-cyanoacrylate fuming (CAF) followed by luminescent dye staining. Relative fingermark detection effectiveness across the two techniques was evaluated via the treatment of 1724 fingermark specimens. It was concluded that, in general, the benchmark method provided superior detection results. It was evident that the SiO 2 NPs are less affected by donor variability but are more dependent on substrate types. Such characteristics are encouraging as they could be favourable to practitioners in casework scenarios where the substrate is known but donor variability is obscure prior to fingermark processing. It should be noted that the overall effectiveness of the proposed NP-based technique will need to be improved before it could be considered for operational implementation., (Copyright © 2020 Elsevier B.V. All rights reserved.)

The application of nanoparticles for latent fingermark detection has been reported in the literature over the past two decades. One of the nanoparticles that shows promise to become a routine technique is functionalised silicon oxide nanoparticles (SiO 2 NPs). In a recent optimisation of the technique, the use of carboxyl-functionalised SiO 2 NPs doped with luminescent ruthenium complex was proposed as a breakthrough for latent fingermark detection. In this study, the aforementioned functionalised SiO 2 NPs were extensively evaluated. Modification and optimisation of the original detection parameters were performed to enhance detection quality and improve applicability. Various detection parameters were evaluated and assessed. A lower concentration of the functionalised nanoparticles used in the colloidal dispersion was determined to offer improved detection effectiveness. A combination of increased bath temperature and reduced immersion time was found to produce good overall results. A set of modified detection parameters was suggested for the use of the functionalised SiO 2 NPs to detect latent fingermarks. Performance of the modified detection parameters was compared against that of the published detection method. Comparison experiments were carried out on fingermark specimens deposited on aluminium foil, transparent polypropylene plastic and green polyethylene plastic. Three donors (weak, average and strong) and two age intervals (ten days and three months) were considered in the comparison study. Evaluation of the results suggested that the overall performance of the modified method for latent fingermark detection was superior to that obtained using the previously published detection parameters., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Single metal deposition (SMD II) is a fingermark detection technique based on the use of colloidal gold. The technique has been simplified and optimised over the years to become more reliable, sensitive and user-friendly. Physical developer (PD) is a well-established detection method based on silver deposition from a redox solution. This study presents an extensive comparison of SMD II against PD for fingermark detection on porous substrates. The two techniques were compared as (i) standalone methods, (ii) in sequence after the application of routine amino acids reagents (1,2-indanedione/zinc followed by ninhydrin), and (iii) after the substrates have been wet. More than 1000 fingermark specimens were processed. Overall, the performance of SMD II was judged to be inferior to that of PD; therefore, SMD II cannot be recommended as a valid replacement for fingermark detection on porous substrates. Indanedione/zinc and ninhydrin application negatively impacts on SMD II performance and the technique gave inconsistent results across the selected range of porous substrates. Moreover, the detected fingermarks lacked contrast making their visualisation difficult. However, even if PD remains the technique of choice, SMD II showed significant potential. It proved to be less affected by donor variability and it can be applied on both porous and non-porous substrates. It did not lead to uncontrolled background staining that commonly occurs with PD. If contrast and consistency issues can be addressed in future research, SMD II may become a viable alternative to PD., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Metal-Organic Frameworks (MOFs) are porous crystalline structures, currently used as sensors, separation membranes, and as catalysts. Due to their physicochemical and optical properties, they have been recently proposed for fingermark detection. This study further explored their potential for fingermark detection. Natural fingermarks, as well as charged and protein-enriched marks, were used to test the efficiency of the technique. Various parameters, such as precursor concentration, pH, immersion time and detection protocols, were investigated and optimised. The performance of the optimised MOF-based method was then compared to that of routinely used techniques. The results obtained indicated that MOFs can effectively detect fingermarks, especially protein-rich marks such as marks contaminated with body fluids. However, after comparison and evaluation against benchmark techniques, results were judged to be inferior to those from currently employed detection methods. However, with further research and optimisation MOFs may be promising as an alternative to current powder suspension techniques., (Copyright © 2018 Elsevier B.V. All rights reserved.)

The primary aims of fingermark detection research are to improve the quality and increase the rate of detection of identifiable impressions. This is usually performed through the development of new methods and technologies to provide alternatives to or improve current procedures. While research of this nature is important to pursue, it fails to address the underlying question related to the factors that affect the detection of a latent fingermark. There has been significant research that has examined the differences between techniques, donors and fingermark age, as well as the composition of latent fingermarks. However, they tend not to focus on determining how these factors influence the quality of the developed mark. This study involved the development and evaluation of over 14,000 natural fingermarks deposited on a variety of surfaces to examine the effect of substrate, age, donor variability (both inter- and intra-), depletions and type of finger on fingermark development. Fingermarks were deposited on four substrates (two non-porous and two porous) and developed with either indanedione-zinc (IND-Zn) or cyanoacrylate followed by rhodamine 6G staining (CA+R6G). Three independent assessors graded each mark on the quality of development using an absolute scale proposed by the UK Centre for Applied Science and Technology (CAST). The data generated from these assessments were then analysed for trends or other useful insights. The results from this work reaffirm that individual substrate characteristics (and the choice of development technique) play a significant role in determining the number and quality of marks developed. It was found that fingermarks were more likely to be detected on porous substrates and to also be of a higher quality than on non-porous. The effect of fingermark donor variability was also explored, with significant differences observed between donors and within donors. This research shows that current detection techniques do not detect all available fingermarks, reinforcing the need for further research into the fundamentals of fingermark detection in order to gain a better understanding of the techniques currently used. The study has identified considerations for the development of novel techniques and how we need to account for variability when designing fingermark research experiments., (Copyright © 2018 Elsevier B.V. All rights reserved.)

In a previous publication we described a systems approach to forensic science applied in the military domain. The forensic science 'system of systems' describes forensic science as a sub-system in the larger criminal justice, law enforcement, intelligence, and military systems, with quality management being an important supporting system. Quality management systems help to ensure that organisations achieve their objective and continually improve their capability. Components of forensic science quality management systems can include standardisation of processes, accreditation of facilities to national/international standards, and certification of personnel. A fit for purpose quality management system should be balanced to allow organisations to meet objectives, provide continuous improvement; mitigate risk; and impart a positive quality culture. Considerable attention over the last decades has been given to the need for forensic science quality management systems to meet criminal justice and law enforcement objectives. More recently, the need for the forensic quality management systems to meet forensic intelligence objectives has been considered. This paper, for the first time, discusses the need for a fit for purpose quality management system for military forensic exploitation., (Crown Copyright © 2018. Published by Elsevier B.V. All rights reserved.)

Hand sanitizers have seen a rapid increase in popularity amongst the general population and this increased use has led to the belief that hand sanitizers may have an effect on subsequent fingermark detection. Based on this hypothesis, three alcoholic and two non-alcoholic hand sanitizers were evaluated to determine the effect they had on the detection of fingermarks deposited after their use. The following fingermark detection methods were applied: 1,2-indanedione-zinc, ninhydrin, physical developer (porous substrate); and cyanoacrylate, rhodamine 6G, magnetic powder (non-porous substrate). Comparison between hand sanitized fingermarks and non-hand sanitized fingermarks showed that the alcohol-based hand sanitizers did not result in any visible differences in fingermark quality. The non-alcoholic hand sanitizers, however, improved the quality of fingermarks developed with 1,2-indanedione-zinc and ninhydrin, and marginally improved those developed with magnetic powder. Different parameters, including time since hand sanitizer application prior to fingermark deposition and age of deposited mark, were tested to determine the longevity of increased development quality. The non-alcoholic hand sanitized marks showed no decrease in quality when aged for up to two weeks. The time since sanitizer application was determined to be an important factor that affected the quality of non-alcoholic hand sanitized fingermarks. It was hypothesized that the active ingredient in non-alcoholic hand sanitizers, benzalkonium chloride, is responsible for the increase in fingermark development quality observed with amino acid reagents, while the increased moisture content present on the ridges resulted in better powdered fingermarks., (Copyright © 2017 Elsevier B.V. All rights reserved.)

To support fingerprint expert opinion, this research proposes an approach that combines subjective human analysis (as currently applied by fingerprint practitioners) with a statistical test of the result. This approach relies on the hypothesis that there are limits to the distortion caused by skin stretch. Such limits can be modelled by applying a multivariate normal probability density function to the distances and angle formed by a marked ridge characteristic and the two closest neighbouring minutiae. This study presents a model tested on 5 donors in total. The "expected range" of distortion in a within-source comparison using 10 minutiae was determined and compared to between-source comparisons. The expected range of log probability densities for within-source comparisons marked with 10 minutiae was determined to be from -33.4 to -60.0, with all between-source data falling outside this range, between -83 and -305. These results suggest that the proposed generated metric could be a powerful tool for the assessment of fingerprint expert opinion in operational casework., (Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.)

A proof-of-concept spectroscopic method for crude and heavy fuel oil asphaltenes was developed to complement existing methods for source determination of oil spills. Current methods rely on the analysis of the volatile fraction of oils by Gas Chromatography (GC), whilst the non-volatile fraction, including asphaltenes, is discarded. By discarding the non-volatile fraction, important oil fingerprinting information is potentially lost. Ten oil samples representing various geographical regions were used in this study. The asphaltene fraction was precipitated from the oils using excess n-pentane, and analysed by Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR). Based on visual interpretation of FTIR spectra along with peak height ratio comparisons, all ten oil samples could be differentiated from one another. Furthermore, ATR-FTIR was not able to differentiate a weathered crude oil sample from its source sample, demonstrating significant potential for the application of asphaltenes in oil fingerprinting., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)

Fingermark enhancement reagents capable of molecular recognition offer a highly selective and sensitive method of detection. Antibodies and aptamers provide a high degree of adaptability for visualisation, allowing for the selection of the most appropriate visualisation wavelength for a particular substrate without the need for specialist equipment or image processing. However, the major hurdle to overcome is the balance between sensitivity and selectivity. Single-target molecular recognition is highly specific, purported to have better detection limits than chemical reactions or stains, and can provide information about the donor or activity, but often results in incomplete ridge pattern development. Consequently, the development and evaluation of multi-target biomolecular reagents for fingermark enhancement was investigated, with the focus on endogenous eccrine secretions. To assess the suitability of the immunogenic reagents for potential operational use, a variety of parameters (i.e., processing time, fixing and working solution conditions) were optimised on a wide range of non-porous and semi-porous substrates. The relative performance of immunogenic reagents was compared to that of routine techniques applied to latent marks and marks in blood, semen and saliva. The incorporation of these novel reagents into routine technique sequences was also investigated. The experimental results indicated that the multi-target immunogenic reagents were not a suitable alternative to routine detection methods or sequences, but may have promise as a "last resort" method for difficult substrates or cases., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)

In the past, forensic soil examination was a routine aspect of forensic trace evidence examinations. The apparent need for soil examinations then went through a period of decline and with it the capability of many forensic laboratories to carry out soil examinations. In more recent years, interest in soil examinations has been renewed due-at least in part-to soil examinations contributing to some high profile investigations. However, much of this renewed interest has been in organisations with a primary interest in soil and geology rather than forensic science. We argue the need to reinstate soil examinations as a trace evidence sub-discipline within forensic science laboratories and present a pathway to support this aim. An examination procedure is proposed that includes: (i) appropriate sample collection and storage by qualified crime scene examiners; (ii) exclusionary soil examinations by trace evidence scientists within a forensic science laboratory; (iii) inclusionary soil examinations by trace evidence scientists within a forensic science laboratory; and (iv) higher-level examination of soils by specialist soil scientists and palynologists. Soil examinations conducted by trace evidence scientists will be facilitated if the examinations are conducted using the instrumentation routinely used by these examiners. Hence, the proposed examination protocol incorporates instrumentation in routine use in a forensic trace evidence laboratory. Finally, we report on an Australian soil scene variability study and a blind trial that demonstrate the utility of the proposed protocol for the effective triage and management of soil samples by forensic laboratories., (Crown Copyright © 2016. Published by Elsevier Ireland Ltd. All rights reserved.)

Physical developer (PD) is a fingermark development technique that involves the selective reduction of silver onto fingermark residue. PD can develop marks on porous substrates even if they have been wet, leading to the logical, long held belief that the reagent targets the water insoluble constituents in the fingermark residue. The present research has tested this hypothesis as part of a broader study that aims to identify the targets of physical developer. Spot tests of some fatty acids, cholesterol and squalene, treated with PD, showed that only cholesterol produced significant silver deposition. PD is known to be particularly effective on aged marks, however cholesterol degrades over time. These observations indicate that PD reactivity with fingermarks cannot solely be due to the presence of cholesterol. Fingermarks were deposited on paper and washed with various organic solvents before being treated with PD. PD effectiveness was intermittent on both solvent washed and unwashed sides of both natural and groomed marks; however, it was seen to effectively develop groomed samples that had been exposed to common lipid extraction solvents, shown to have removed the lipids by visualisation using the lipid stain Nile red. PD effectiveness was most affected by exposure of samples to solvents that could dissolve water soluble components, showing that the removal of these constituents (by either water, or other solvents) decreases the amount of silver deposited on the fingermark residue by the working solution. Close observation of PD developed samples showed variation in silver deposition uniformity when comparing a developed ridge to a pore site located on that ridge. Some samples showed an absence of silver, and other showed an increase of silver at pore locations. This indicates that the material excreted by the pores on the finger has an effect on silver deposition, suggesting that PD may be specifically targeting eccrine constituents that are present along the ridges but are more concentrated at the pore locations. These findings indicate that PD is not targeting the lipids in the fingermark residue per se, and may instead be targeting eccrine constituents or a more complex mixture of both eccrine and lipid constituents. Further investigation is underway within our group to investigate the components targeted by PD to gain a better understanding of what is a notoriously sensitive and hard to employ technique in the hope that it can be improved or simplified, or alternatives identified., (Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.)

Physical developer (PD) is a fingermark development technique that deposits silver onto fingermark ridges. It is the only technique currently in routine operational use that gives results on porous substrates that have been wet. There is a reasonable understanding of the working solution chemistry, but the chemical constituent(s) contained in fingermark residue that are specifically targeted by PD are largely unknown. A better understanding of the PD technique will permit a more informed selection of alternative or complementary detection methods, and greater usage in operational laboratories. Recent research by our group has shown that PD does not selectively target the lipids present in the residue. This research investigated the hypothesis that PD targets the eccrine constituents in fingermark residue. This was tested by comparison of PD and indanedione-zinc (Ind-Zn) treated natural fingermarks that had been deposited successively, and marks that had been deposited with a ten second interval in between depositions. Such an interval allows for the regeneration of secretions from the pores located on the ridges of the fingers. On fingermark depletions with no time interval between depositions, PD and Ind-Zn treated depletions successively (and comparatively) decreased in development intensity as the amount of residue diminished. Short time intervals in between successive depletions resulted in additional secretions from the pores intermittently occurring, the increased development of which was visualised by treatment with both PD and Ind-Zn. The changes in development intensity were seen with both techniques on the same split depletions in a series, comparably and proportionately. These results indicate that the components targeted by PD are contained in the material excreted by the friction ridge pores through its mirrored development with Ind-Zn. Repetition of the experiments on marks that only contained eccrine material showed good Ind-Zn development but poor results with PD. This indicates that there are other constituents contained in "natural" fingermarks that are required to be present for PD to be able to target constituents in the eccrine sweat. It may be that the required constituents in the natural residues are non-water soluble, and that these protect the eccrine constituents from solubilisation in the aqueous washes employed in the PD method. Further research is being undertaken to determine whether PD is targeting specific compounds in the pore secretions, or a mixture of compounds consisting of the eccrine material, epidermal lipids and sebaceous lipids typically present in latent fingermark residues., (Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.)

Despite significant ongoing research, a substantial proportion of latent fingermarks remain undetected in casework. Therefore, to improve existing detection techniques and to allow the development of new approaches, it is important to gain a better understanding of detection mechanisms rather than solely focusing on method formulations. As a starting point, it is crucial to gain a deeper understanding of the fingermark residue itself. Even if the chemical composition is reasonably well understood, little research has been reported on the physical aspects related to the deposition of fingermarks and their interactions with the environment and underlying substrates. This study aimed at exploring various techniques that can be used for the non-destructive visualisation of fingermarks before applying detection techniques. Both light and electron microscopy were investigated. Phase contrast imaging and environmental scanning electron microscopy, coupled with energy-dispersive X-ray spectrometry, proved to be essential tools for the study of latent fingermark deposits. These methods can be used to gather fundamental information that will add to our body of knowledge in this field., (Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.)

Document examination is an important forensic discipline and the legal system regularly needs the knowledge and skills of the scientific expert when questioned documents are involved in criminal or civil matters. Amongst the many aspects of the scientific examination of documents, elemental analysis can provide useful results. In this study, the evaluation of the analytical performance of a commercially available laser-induced breakdown spectroscopy (LIBS) instrument was conducted on office papers, writing inks, inkjet inks and laser printer toners. The paper sample set analysed consisted of 33 Australian paper specimens originating from the same production plant but representing different brands and/or batches. In addition, a total of 131 ink or toner samples were examined that included black and blue ballpoint inks, black inkjet inks, and black laser printer toners originating from several manufacturing sources, models and/or batches. Results from the LIBS method were compared against those obtained using more established elemental profiling method such as laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). LIBS demonstrated detectable and significant differences between different batches of the same brand as well as between different brands of paper, ink and toner samples. The LIBS method provided comparable discrimination powers for the selected sample sets when compared to those obtained using LA-ICP-MS (discrimination from 99.8 and 100% of the sample pairs, depending on the sample subset under examination). LIBS is a suitable technique for the determination of elemental composition as part of a protocol for the examination of questioned documents., (Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.)

Laser-induced breakdown spectroscopy (LIBS) is an emerging atomic emission based solid sampling technique that has many potential forensic applications. In this study, the analytical performance of LIBS, as well as that of inductively coupled plasma mass spectrometry (ICP-MS), laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and X-ray microfluorescence (μXRF), was evaluated for the ability to conduct elemental analyses on Cannabis plant material, with a specific investigation of the possible links between hydroponic nutrients and elemental profiles from associated plant material. No such study has been previously published in the literature. Good correlation among the four techniques was observed when the concentrations or peak areas of the elements of interest were monitored. For Cannabis samples collected at the same growth time, the elemental profiles could be related to the use of particular commercial nutrients. In addition, the study demonstrated that ICP-MS, LA-ICP-MS and LIBS are suitable techniques for the comparison of Cannabis samples from different sources, with high discriminating powers being achieved. On the other hand, μXRF method was not suitable for the discrimination of Cannabis samples originating from different growth nutrients., (Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.)

Most spectroscopic studies of the reaction products formed by ninhydrin, 1,2-indanedione-zinc (Ind-Zn) and 1,8-diazafluoren-9-one (DFO) when reacted with amino acids or latent fingermarks on paper substrates are focused on visible absorption or luminescence spectroscopy. In addition, structural elucidation studies are typically limited to solution-based mass spectrometry or liquid nuclear magnetic resonance (NMR) spectroscopy, which does not provide an accurate representation of the fingermark development process on common paper substrates. The research presented in this article demonstrates that solid-state carbon-13 magic angle spinning NMR ((13)C-MAS-NMR) is a technique that can not only be utilised for structural studies of fingermark enhancement reagents, but is a promising technique for characterising the effect of paper chemistry on fingermark deposition and enhancement. The latter opens up a research area that has been under-explored to date but has the potential to improve our understanding of how fingermark secretions and enhancement reagents interact with paper substrates., (Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.)

Laser-induced breakdown spectroscopy (LIBS), X-ray fluorescence spectroscopy (XRF) and scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDX) are compared in terms of their discrimination power when applied to Australian soil specimens. SEM/EDX and XRF are frequently used in forensic laboratories for the elemental analysis of paint and glass, and for miscellaneous examinations. LIBS is an emerging technique for forensic applications, with a number of researchers promoting its use for the elemental profiling of glass fragments. In this study, 29 soil specimens were analysed, with 12 specimens coming from the Canberra area and the remaining 17 specimens from other sites around Australia. As very good discrimination results were obtained for each of the analytical methods, any of these elemental analysis techniques, available in a trace evidence laboratory, could be used as part of a wider examination protocol to differentiate soil specimens., (Crown Copyright © 2014. Published by Elsevier Ireland Ltd. All rights reserved.)

In the past, forensic soil examination was a routine aspect of trace evidence examination in forensic science. However, in Australia, the apparent need for soil examinations has diminished and with it the capability of forensic science laboratories to carry out soil examination has been eroded. In recent years, due to soil examinations contributing to some high profile investigations, interest in soil examinations has been renewed. Routine soil examinations conducted in a forensic science laboratory by trace evidence scientists can be facilitated if the examinations are conducted using the instrumentation routinely used by these examiners. Spectroscopic techniques such as visible microspectrophotometry (MSP) and Attenuated Total Reflectance (ATR) Fourier Transform Infrared spectroscopy (FTIR) are routinely used by trace evidence analysts for the colour and compositional analysis, respectively, of forensic items, including paints, fibres, inks and toners, tapes, adhesives and other miscellaneous examinations. This article presents an examination of the feasibility of using MSP and ATR-FTIR as a first step in the forensic comparison of soils with particular reference to Australian soil samples. This initial study demonstrates MSP and ATR-FTIR can effectively be used as a screening test for the discrimination of "forensic-sized" soil samples prior to submission for more detailed analyses by a soil expert., (Crown Copyright © 2014. Published by Elsevier Ireland Ltd. All rights reserved.)

An oil-in-water microemulsion containing a luminescent dye, nile red, has been synthesised using a solvent-diffusion method. This has been demonstrated to be effective in developing fresh latent fingermarks on porous surfaces. The working solution is made using a binary surfactant solution to create a lactescent dual organic-aqueous phase intermediate, which subsequently results in a transparent microemulsion after the organic solvent has evaporated. The solution is non-toxic and performs comparatively with a previously published methanolic formulation but at a much lower cost and with an extended shelf life. The microemulsion outperforms a previously reported aqueous nile blue formulation for the development of both charged and natural fresh fingermarks, and requires lower exposure times for image recording., (Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.)

A commercially available laser-induced breakdown spectroscopy (LIBS) instrument was evaluated for the determination of elemental composition of twenty Australian window glass samples, consisting of 14 laminated samples and 6 non-laminated samples (or not otherwise specified) collected from broken windows at crime scenes. In this study, the LIBS figures of merit were assessed in terms of accuracy, limits of detection and precision using three standard reference materials (NIST 610, 612, and 1831). The discrimination potential of LIBS was compared to that obtained using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), X-ray microfluorescence spectroscopy (μXRF) and scanning electron microscopy energy dispersive X-ray spectrometry (SEM-EDX) for the analysis of architectural window glass samples collected from crime scenes in the Canberra region, Australia. Pairwise comparisons were performed using a three-sigma rule, two-way ANOVA and Tukey's HSD test at 95% confidence limit in order to investigate the discrimination power for window glass analysis. The results show that the elemental analysis of glass by LIBS provides a discrimination power greater than 97% (>98% when combined with refractive index data), which was comparable to the discrimination powers obtained by LA-ICP-MS and μXRF. These results indicate that LIBS is a feasible alternative to the more expensive LA-ICP-MS and μXRF options for the routine forensic analysis of window glass samples., (Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.)

It is generally accepted that the amino acid reagent consisting of 1,2-indanedione and a catalytic amount of zinc chloride, referred to as IND-Zn, is the single best method for the detection of latent fingermarks on paper substrates and that ninhydrin is of limited value when used in sequence after this reagent. However, recent research has suggested that the sequence 1,8-diazafluoren-9-one (DFO) followed by ninhydrin may actually produce a greater number of fingermarks than IND-Zn on its own or IND-Zn followed by ninhydrin. This study focussed on the evaluation of two fingermark detection sequences for porous surfaces: (1) IND-Zn followed by ninhydrin, physical developer (PD) and the lipid stain nile red; and (2) DFO followed by ninhydrin, PD and nile red. The evaluation was undertaken using a range of latent fingermark donors and on a number of paper substrates that are commonly encountered in Australia. In addition, a pseudo-operational trial was completed on 5-year-old university examination booklets. Parallel studies were undertaken at two locations: Sydney (temperate, coastal climate) and Canberra (relatively dry, continental climate). The results of the donor study indicated that there was a negligible difference in performance between the two sequences across all paper types and all time periods evaluated. When considering individual reagents, IND-Zn generally developed better quality fingermarks compared to DFO; however, ninhydrin had a greater enhancement effect on DFO developed marks than after IND-Zn. In the pseudo-operational trials, the IND-Zn sequence outperformed the DFO sequence. Nile red did not develop any additional marks at the end of each sequence and, as a result, the use of this technique at the end of a full sequence is of questionable value. The overall outcome was that the sequence IND-Zn followed by ninhydrin and PD is recommended for the processing of common paper substrates under the conditions typically experienced at the two locations studied., (Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.)

An offender who has recently handled bulk explosives would be expected to deposit latent fingermarks that are contaminated with explosive residues. However, fingermark detection techniques need to be applied in order for these fingermarks to be detected and recorded. Little information is available in terms of how routine fingermark detection methods impact on the subsequent recovery and analysis of any explosive residues that may be present. If an identifiable fingermark is obtained and that fingermark is found to be contaminated with a particular explosive then that may be crucial evidence in a criminal investigation (including acts of terrorism involving improvised explosive devices). The principal aims of this project were to investigate: (i) the typical quantities of explosive material deposited in fingermarks by someone who has recently handled bulk explosives; and (ii) the effects of routine fingermark detection methods on the subsequent recovery and analysis of explosive residues in such fingermarks. Four common substrates were studied: paper, glass, plastic (polyethylene plastic bags), and metal (aluminium foil). The target explosive compounds were 2,4,6-trinitrotoluene (TNT), pentaerythritol tetranitrate (PETN), and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), as well as chlorate and nitrate ions. Recommendations are provided in terms of the application of fingermark detection methods on surfaces that may contain explosive residues., (Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.)

Over the last decade, the development of statistical models in support of forensic fingerprint identification has been the subject of increasing research attention, spurned on recently by commentators who claim that the scientific basis for fingerprint identification has not been adequately demonstrated. Such models are increasingly seen as useful tools in support of the fingerprint identification process within or in addition to the ACE-V framework. This paper provides a critical review of recent statistical models from both a practical and theoretical perspective. This includes analysis of models of two different methodologies: Probability of Random Correspondence (PRC) models that focus on calculating probabilities of the occurrence of fingerprint configurations for a given population, and Likelihood Ratio (LR) models which use analysis of corresponding features of fingerprints to derive a likelihood value representing the evidential weighting for a potential source., (Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.)

The detection and identification of volatile compounds is essential to the successful undertaking of numerous forensic analyses. Biological olfactory systems possess the extraordinary ability to not only detect many thousands of distinct volatile compounds (odors) but also to discriminate between them. Whole-organism biological sensors, such as detection canines, have been employed in forensic science as volatile compound detectors for many years. A variety of insects including bees, wasps, and moths, which have also been shown to detect volatile compounds of forensic significance, have been investigated for their potential application in field-based detection systems. While the fundamental aim for many developers of portable instruments is to replicate the remarkable ability of biological olfactory systems, such analytical equipment is yet to possess the detection and discriminatory powers achieved by biological sensors. Recent literature reveals an increasing interest in olfactory receptors - the biological components that impart olfactory ability - for detecting volatile compounds associated with forensically significant substances such as explosives and illicit drugs. This paper reviews the literature regarding the current, and potential future, use of biological organisms as sensors for forensic science applications., (Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.)

The development of statistical models for forensic fingerprint identification purposes has been the subject of increasing research attention in recent years. This can be partly seen as a response to a number of commentators who claim that the scientific basis for fingerprint identification has not been adequately demonstrated. In addition, key forensic identification bodies such as ENFSI [1] and IAI [2] have recently endorsed and acknowledged the potential benefits of using statistical models as an important tool in support of the fingerprint identification process within the ACE-V framework. In this paper, we introduce a new Likelihood Ratio (LR) model based on Support Vector Machines (SVMs) trained with features discovered via morphometric and spatial analyses of corresponding minutiae configurations for both match and close non-match populations often found in AFIS candidate lists. Computed LR values are derived from a probabilistic framework based on SVMs that discover the intrinsic spatial differences of match and close non-match populations. Lastly, experimentation performed on a set of over 120,000 publicly available fingerprint images (mostly sourced from the National Institute of Standards and Technology (NIST) datasets) and a distortion set of approximately 40,000 images, is presented, illustrating that the proposed LR model is reliably guiding towards the right proposition in the identification assessment of match and close non-match populations. Results further indicate that the proposed model is a promising tool for fingerprint practitioners to use for analysing the spatial consistency of corresponding minutiae configurations., (Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.)

This paper describes the application of a luminescent lipid stain, nile red, for the development of latent fingermarks on porous surfaces. An optimised formulation is presented that provides rapid development of latent fingermarks on porous surfaces that are or have been wet. A comparison with physical developer (PD), the method of choice to enhance such fingermarks, indicated that nile red was a simpler and more stable technique for the development of fingermarks. The nile red formulation showed similar performance to PD across a range of substrates and ageing conditions, although PD still showed greater sensitivity on five-year-old examination booklets used in a pseudo-operational study. The pseudo-operational trial also indicated that nile red consistently developed different fingermarks to those enhanced by PD, suggesting that it preferentially targets a different fraction of the latent fingermark deposit. Significantly, the compatibility of nile red in a detection sequence with indanedione-zinc, ninhydrin and PD is reported., (Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.)

The stability of four target organic explosives [pentaerythritol tetranitrate (PETN), 2,4,6-trinitrotoluene (TNT), hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) and triacetone triperoxide (TATP)] and two inorganic anions (chlorate and nitrate) on polyester-based alcohol wipes and in 60% (v/v) methanol/water extracts, stored over 30 days in clear and amber glass vials at three different temperatures, was investigated in order to establish storage recommendations. The retention of all six representative compounds on a glass surface at two different storage temperatures was also included as a preliminary study on the stability of explosive residues on stored exhibits (such as post-blast debris). The results from the stability study suggested that, after sampling, the wipes should be stored in a dark and low temperature environment. Also, after extracting the wipes with 60% (v/v) methanol/water (as in our previously reported recommended protocol), the extracts should be stored in a similar fashion. The results from the retention study on the glass substrate suggested that exhibits should be stored at the lowest temperature possible to minimise the loss of TNT or TATP (or similar target compounds) that might be present as residues., (Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.)

A single-step solvent extraction and a solid-phase extraction (SPE) clean-up procedure was developed and optimised in order to establish a universal sampling and clean-up protocol for the combined recovery of organic and inorganic explosive residues. Mixtures of three common swabbing solvents (acetone, acetonitrile and methanol) with water, in various ratios, were assessed for the extraction of four target organic explosives [pentaerythritol tetranitrate (PETN), 2,4,6-trinitrotoluene (TNT), hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) and triacetone triperoxide (TATP)] and two inorganic anions (chlorate and nitrate) from alcohol wipes that were used as a swabbing medium. An efficient, single-step extraction of both organic and inorganic compounds from the wipes was achieved using 60% v/v methanol/water. To develop a clean-up procedure, four commercially available SPE cartridges (Oasis HLB, Isolute(®) C18, Bond-Elut(®) ENV and ABS ELUT Nexus) and an in-house packed XAD-7 cartridge were firstly evaluated for their retention capacity toward three organic explosives (PETN, TNT and RDX) in a mixture of methanol and water. A SPE technique was then developed and optimised from the short-listed sorbents with four representative organic explosives (including TATP). The Nexus cartridge was found to provide a suitable sorbent for extract clean-up following swab extraction with 60% v/v methanol/water. By incorporating the optimised clean-up procedure with the application of a polyester-based alcohol wipe as a sampling medium, a universal swabbing protocol for the combined recovery of both organic and inorganic explosive residues was established. The feasibility of the proposed protocol was assessed by collection and quantitation of the residue from a mixture of TNT, PETN and chlorate deposited on a laminate test surface., (Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.)

Commercially available skin cleansing alcohol wipes and conventional swabs were investigated for their use as a universal sampling medium for the simultaneous collection of both organic and inorganic explosive residues. Six compounds with the potential to be encountered in casework [pentaerythritol tetranitrate (PETN), 2,4,6-trinitrotoluene (TNT), hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), triacetone triperoxide (TATP), ammonium nitrate, and sodium chlorate] were selected as representative target compounds. Quantities of these target compounds were deposited on four different substrates (glass, plastic, aluminium foil and laminate). Two chosen alcohol wipes demonstrated better overall performance in the recovery of both the organic and inorganic representative compounds from each of the test surfaces compared to the results obtained using conventional cotton and polyester swabs, pre-moistened with various solvents, and a direct methanol wash (used as a control). Results obtained using dry cotton swabs indicated that it was not an effective swabbing system for the collection of both organic and inorganic explosive residues on common substrates., (Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.)

Conventional fingermark powders rely on contrast induced by absorption/reflection (e.g. black powder) or luminescence in the visible region (e.g. Blitz Green(®)). In most cases, these powders provide sufficient contrast; however, in some circumstances surface characteristics can interfere with the visualisation of powdered fingermarks. Visualisation in the near infra-red (NIR) region, however, has been shown to eliminate interferences commonly encountered in the visible region. In this study, a mixture of rhodamine 6G and the NIR laser dye styryl 11 (STaR 11) was coated onto an aluminium oxide nanopowder and then mixed with silver magnetic powder to develop and visualise fingermarks in the NIR. When compared to Blitz Green(®), it was determined that the STaR 11 magnetic powder was better suited for marks deposited on textured surfaces and for older marks, whereas Blitz Green(®) performed better on smooth glossy surfaces. The ability of the STaR 11 mixed dye formulation to be visualised in both the visible and NIR regions also provides a significant advantage over conventional luminescent fingermark powders., (Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.)

This article describes the use of an anti-Stokes luminescent material (upconverter), yttrium vanadate doped with ytterbium and erbium (YVO(4):Er,Yb), for the development of latent fingermarks on a range of non-porous surfaces. Anti-Stokes luminescent materials emit light at shorter wavelengths than the excitation wavelength. This property is unusual in both natural and artificial materials commonly found as exhibits in forensic science casework. As a result, fingermark detection techniques based on anti-Stokes luminescence are potentially extremely sensitive and selective. Latent fingermarks on non-luminescent and inherently luminescent substrates, including Australian polymer banknotes (a well-known 'difficult' surface), were developed with YVO(4):Er,Yb by dry powder and wet powder techniques. The effectiveness of YVO(4):Er,Yb for fingermark detection was compared with that of cyanoacrylate fuming and of sodium yttrium tetrafluoride doped with ytterbium and erbium (NaYF(4):Er,Yb). The results illustrate some benefit of luminescent up-converting phosphors over traditional luminescence techniques for the detection of latent fingermarks., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

Cyanoacrylate fuming is one of the most common techniques employed for the detection of latent fingermarks on non-porous surfaces such as plastic and glass. The technique is generally applied by exposing items of interest to the vapours generated by heating a suitable quantity of commercial cyanoacrylate adhesive. In this study, the potential for highly toxic hydrogen cyanide (HCN) to be generated from the overheating of cyanoacrylate was investigated. Two commercial cyanoacrylate adhesives and two quantitative methods for the determination of HCN were employed: (i) the sodium picrate method; and (ii) the picrate-resorcinol method. (13)C nuclear magnetic resonance (NMR) analysis was used to confirm the presence of cyanide. In addition, the thermal decomposition of cyanoacrylate was studied using simultaneous thermogravimetric and differential thermal analysis (TGA-DTA). It was determined that detectable and quantifiable amounts of HCN were generated from the thermal decomposition of cyanoacrylate monomer and polymer at temperatures as low as 200 °C. Using an optimised picrate-resorcinol method, it was shown that around 10 μg of HCN could be generated from the heating of 1g of cyanoacrylate monomer at 200 °C. For one of the adhesives tested, this increased to above 100 μg of HCN when 1g of cyanoacrylate monomer was heated at 280 °C. Recommendations are provided that, if followed, should ensure that the cyanoacrylate fuming process can be safely applied with minimal risk to the operator., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

Anecdotal evidence from forensic practitioners and studies conducted under controlled conditions have indicated that the reaction between 1,2-indanedione and the amino acids present in latent fingermark deposits is highly susceptible to ambient humidity. The addition of catalytic amounts of zinc chloride to the 1,2-indanedione working solution--usually in the order of 1:25 to 1:4 molar ratio (indanedione:zinc)--significantly improves the colour and luminescence of fingermarks treated under dry conditions but appears to have a negligible effect on fingermarks treated in humid environments. The results presented in this paper confirmed that zinc(II) ions added to the 1,2-indanedione working solution act as a Lewis acid catalyst, stabilising a key intermediate during a rate-limiting hydrolysis step. Furthermore, studying the reaction using a chromatography-grade cellulose substrate method previously reported confirmed that cellulose substrates play a major role in facilitating the indanedione-amino acid reaction by acting as a surface catalyst in the early stages of the reaction and by directing the formation of the desired luminescent product (Joullié's Pink)., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

This article describes the first use of an anti-Stokes material, or up-converter, for the development of latent fingermarks on a range of non-porous surfaces. Anti-Stokes materials can absorb long-wavelength light and emit light at a shorter wavelength. This property is unusual in both natural and artificial materials and so fingermark detection techniques based on anti-Stokes luminescence are potentially sensitive and selective. Latent fingermarks on luminescent and non-luminescent substrates, including Australian polymer banknotes (a well-known 'difficult' surface), were developed with sodium yttrium tetrafluoride doped with erbium and ytterbium (NaYF(4):Er,Yb) by dry powder, wet powder, and cyanoacrylate staining techniques. This study illustrates the potential of up-converter phosphors for the detection of latent fingermarks., (Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.)

A new, highly fluorescent dye was synthesised using oleylamine combined with a perylene dianhydride compound. The new dye was characterised by 1H NMR, UV-vis spectroscopy and fluorescence spectroscopy as well as quantum yield. The dye was absorbed onto titanium dioxide nanoparticles for use as a fingerprint detection powder. The new fluorescent powder was applied to latent fingermarks deposited onto different non-porous surfaces and compared with commercial fluorescent powders. The powder exhibits strong fluorescence at 650-700 nm under excitation at 505 nm. On glass surfaces, the new powder gave images showing tertiary-level detail of the fingermark ridges with almost no background development. Compared with current magnetic fluorescent powders, the new powder was slightly weaker in fluorescence intensity but produced significantly less background development, resulting in good contrast between the fingermark and the substrate.

Vacuum metal deposition (VMD) is a well-established technique that can be used for the development of latent fingermarks on a range of polymer surfaces, including polyethylene (PE) bags exposed to harsh environmental conditions. The technique has also proved to be effective on difficult semi-porous surfaces such as the polymer banknotes in circulation in Australia and in an increasing number of other countries. VMD is a two-stage technique. In the first stage, a small amount of gold is deposited under high vacuum onto the exhibit. This is then followed by the deposition, onto the gold layer, of a much thicker layer of zinc. Normal VMD development is characterised by zinc depositing all over the surface except on the fingermark ridges themselves. A phenomenon of reverse development (zinc on the ridges but not on the surface) has been reported by many authors. Recent studies indicated that this phenomenon might occur on low-density polyethylene (LDPE) when the amount of deposited gold is above an optimum quantity. The results suggested that the size of the gold agglomerates formed on the surface of the polymer plays a critical role. This preliminary study was aimed at visualising, by transmission electron microscopy (TEM), the formation of gold agglomerates on polymer surfaces to gain an appreciation of how the density and size of these agglomerates changes with an increasing amount of evaporated gold.

1,2-indanedione is an emerging fingermark reagent used on porous surfaces. The general consensus is that this reagent is at least as sensitive as DFO, with some research showing higher sensitivity for 1,2-indanedione as opposed to DFO. However, a number of discrepancies existed in the literature as to which formulation and which development procedure produces optimal results. This project set out to investigate the best formulation and development procedure under Australian conditions, encompassing all published recommendations as well as some novel approaches. 1,2-indanedione formulations were compared with respect to initial colour, fluorescence, concentration of reagent, acetic acid concentration, and the effect of different carrier solvents. Numerous development conditions were investigated, including a conventional oven, a heat press and humidity. Further enhancement using metal salt treatment and liquid nitrogen was also evaluated. The heat press set at 165 degrees C for 10s proved to give the best initial colour and most intense luminescence. Secondary metal salt treatment improved initial colour and luminescence. The Polilight, the VSC 2000, and the Condor Chemical Imaging macroscope have been used to detect the fingerprints developed with 1,2-indanedione on a variety of high- and low-quality porous and semi-porous surfaces, with impressive results overall. Laboratory and field tests were conducted to compare 1,2-indanedione with DFO and ninhydrin as well as to investigate the position of 1,2-indanedione in the sequence of reagents for fingermark detection on porous surfaces. Overall, 1,2-indanedione proved to be a viable alternative to traditional methods for the detection of fingermarks on porous surfaces, with more fingermarks being developed using this reagent on real samples than both DFO and ninhydrin and a combination of the two reagents.

The key role of a forensic scientist is to assist in determining whether a crime has been committed, and if so, assist in the identification of the offender. Many people hold the belief that a particular item can be conclusively linked to a specific person, place or object. Unfortunately, this is often not achievable in forensic science. In performing their role, scientists develop and test hypotheses. The significance of those hypotheses that cannot be rejected upon completion of all available examinations/analyses is then evaluated. Although one can generally identify the substances present using available techniques, it is generally not possible to distinguish one source of the same substance from another. In such circumstances, although a particular hypothesis cannot be rejected, it cannot be conclusively proven, i.e. the samples could still have originated from different sources. This limitation of not being able to distinguish between sources currently extends to the analysis of other forensic samples including, but not limited to, ignitable liquids, paints, adhesives, textile fibres, plastics, and illicit drugs. Stable isotope ratio mass spectrometry (IRMS) is an additional technique that can be utilised to test a given hypothesis. This technique shows the potential to be able to individualise a range of materials of forensic interest. This paper provides a brief description of the technique, followed by a review of the various applications of IRMS in different scientific fields. The focus of this summary is on forensic applications of IRMS, in particular the analysis of explosives, ignitable liquids and illicit drugs.

A feasibility study of short tandem repeat (STR) genotyping of telogen phase hairs in particular, and hair shaft in general, is presented. A number of extraction procedures in common use were investigated and the quantities of nuclear DNA (nuDNA) delivered were quantified via a real-time PCR assay. The extracts were subjected to two variations on AmpFlSTR Profiler Plus PCR amplification strategies (extended cycles, two rounds of PCR) and the genotypes compared. Nuclear DNA was found to persist in human hair shafts, albeit at very low levels. Full Profiler Plus profiles consistent with the hair donor were obtained from 100 mg hair shaft samples (bleached and unbleached). These were, however, mixed profiles, indicating low copy number (LCN) contamination in the extracts. Single telogen hair clubs and single hair shafts delivered partial profiles with usually only one allele of heterozygous loci. Telogen phase hairs yielded the same amount of nuDNA (and no more) as hair shafts (either anagen or telogen). Whether hair shafts dissolved or not in lysis buffer had no effect on either the quantitated yield of DNA or on the chance of obtaining a correct genotype. These results provide evidence that genomic DNA resides on the exterior of the hair shaft and we use this information to suggest an optimal procedure for nuDNA extraction from keratinised hair samples: soaking hairs in simple digestion buffers containing Tris-HCl, a salt and a chelating agent without prior cleaning of the hair shafts. It is proposed that cleaning removes most of the recoverable DNA. This procedure was applied to obtain genotypes from 3 cm hair shafts which matched reference profiles from the donors at up to 9 out of 10 AmpFlSTR Profiler Plus STR loci. When the genotyping success was measured by counting the number of matches between the two dominant alleles at each locus for each extract with the reference DNA profile of the hair donor, the success was found to be highly dependent on the donor. The number of matching alleles varied between not less than 10 for one donor to no more than two for another donor. These results may well be linked to the environmental experience of the hairs from each donor prior to removal.

We present a review of the literature on procedures for obtaining short tandem repeat (STR) genotypes from keratinised hair, being either hair shaft or telogen phase (naturally shed) hairs without associated scalp, follicle or sheath cells. Both the hair shaft and the telogen hair club have been subjected to the DNA-degrading keratinisation process and are more likely to be found at a crime scene than anagen (plucked) or catagen phase hairs. We discuss human hair structure, the human hair growth cycle, the keratinisation process and their implications for DNA extraction procedures, PCR amplification strategies and the interpretation of STR genotypes. Knowledge gaps and areas requiring research are identified and are the subject of a second article in this series.

This study investigated the application of chemical imaging to the detection of latent fingerprints using the Condor macroscopic chemical imaging system (ChemImage Corp., Pittsburgh, USA). Methods were developed and optimised for the visualisation of untreated latent fingerprints and fingerprints processed with DFO, ninhydrin, cyanoacrylate, and cyanoacrylate plus rhodamine 6G stain. The results obtained with chemical imaging were compared to the detection achieved using conventional imaging techniques. The Condor significantly improved the detection of many prints, especially those that might be considered poor quality or borderline prints. Prints on newspaper treated with ninhydrin and DFO, and prints on white and yellow paper treated with ninhydrin, benefited the most from chemical imaging detection. In many cases, fingerprints undetectable using conventional imaging techniques could be visualised with chemical imaging. Ridge detail from untreated prints on yellow paper was also detected using the Condor. When prints of high quality were examined, both detection techniques produced quality results. The results of this project demonstrate that chemical imaging offers advantages over conventional visualisation techniques when examining latent fingerprints, especially those that would be considered difficult, such as weak prints or prints on surfaces that produce highly luminescent backgrounds. Standard testing procedures for the detection and enhancement of fingerprints by chemical imaging are presented and discussed.

The significance of the presence of petrol in motor vehicle fires has often been challenged due to the possibility of a natural occurrence of petrol residues inside the vehicle. Transfer and persistence studies were undertaken to investigate the potential transfer and persistence of petrol onto vehicle carpets through the 'normal' usage of motor vehicles. The results of the transfer study indicate that petrol may be transferred from the external environment in sufficient quantities via the shoes of drivers or passengers to be detected after a 24 h period, but not after 1 week. Low levels of petrol were detectable after 24 h on all carpet mats where the initial volume was 500 microL or more. The level of evaporation of the petrol detected increased with corresponding increases in the time period between transfer and analysis. The results of the persistence study indicate that small volumes of petrol (less than 100 microL) are unlikely to be detected on carpet after a 24 h period, and volumes of less than 1000 microL are unlikely to be detected on acoustic padding after this time period. Larger volumes may be detected after this period, but will generally not be detectable on either carpet or acoustic padding after 4 weeks. In each case, the petrol that is detected exhibits a chromatographic profile of greater than 60% evaporated petrol. These results demonstrate the significance of finding a large volume of fresh or slightly evaporated petrol on car carpet.

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.

A previously identified difficulty with the development of latent fingerprints on low-density polyethylene (LDPE) by vacuum metal deposition (VMD) is that excess gold deposition prevents effective zinc deposition and so inhibits latent print development [1]. The investigation of a means to correct for excess gold deposition was the basis for this study. Exposure to zinc and the readmission of air into the vacuum chamber followed by VMD development results in the deactivation of the initial gold clusters due to the formation of zinc oxide and the adsorption of air and water molecules. As a result, the majority of the gold deposited during the second treatment creates new gold clusters rather than adding to the gold clusters previously formed. After excess gold deposition on LDPE, the deposition of 1.5 times the optimum gold amount will result in good-quality normal development. The results also indicate that, on all surfaces, at least twice the initial gold count should be used for re-treatment when further development is required after air has been readmitted to the chamber.

Ninhydrin developed fingerprints can be enhanced by treatment with a zinc or cadmium salt. The resulting fingerprint 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-fluorenone (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 24 degrees. 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 fingerprints. 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.

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. On group II plastics, results suggest that the gold clusters are smaller and more densely packed. Hence, even though the same amount of gold has been deposited, the gold clusters in this case do not reach the critical morphology and so continue to act as nucleation sites for zinc.Typically, zinc will not deposit onto the fingerprint ridges as the gold nucleation sites are buried within the print residue. However, when more gold is deposited, gold emerges at the surface of the latent print allowing zinc deposition onto the ridges. The rate of gold evaporation was found not to affect the structure of the gold film, although a slower rate of evaporation resulted in more effective deposition.