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Iron oxide powder suspension (FePS) is a fingermark development technique that can be used on adhesive and non-porous surfaces, the efficacy of which is known to be influenced by the surfactant used in the formulation. Despite previous work optimising surfactants for use in FePS, there is limited understanding of the interactions between surfactants, powders and fingermark residue which aid the successful development of fingermarks. To better understand the effect of surfactant on development quality produced by FePS, this research assessed a wide range of surfactants of different ionic natures and evaluated their ability to develop fingermarks based on the quality of ridge detail, contrast and background development produced. It was found that surfactants play a critical role in the selective deposition of powder on fingermark residue, as formulations made with only water (no surfactant) produced heavy background deposition. The efficacy of each surfactant depended on the quality parameter considered, and the addition of some surfactants hindered fingermark development. Effective surfactants such as T20, KP and TX100 prevented background development and produced well contrasted developed marks. Poor contrast was produced by LN, SP80/T80 and T80 due to indiscriminate powder deposition either across the entire sample or preventing any powder to deposit on the surface, demonstrating the role surfactants play in allowing powder deposition in this technique. The effectiveness of a surfactant in PS was not directly dependent on its ionic nature, and most surfactants were more effective when diluted from stock concentrations. This research has provided a robust base for future work improving fundamental understanding of FePS, which will greatly aid the efficacy of future optimisation efforts.

From the beginnings of Silk Road in 2011, anonymous online marketplaces have continued to grow despite the best efforts of law enforcement. While these ever-present marketplaces remain flooded with illicit drugs and related paraphernalia, the sale and distribution of fraudulent identity documents remains a persistent problem, with these items consistently appearing for sale on both the open and dark web. While fraudulent Australian documents are some of the most popular products for sale, there is still much that is unknown about the Australian criminal market and its place within anonymous online marketplaces. Given the success of previous research in understanding the illicit drug trade through examining these marketplaces, this work examines two markets to gain an understanding of where Australian document fraud sits within this digital ecosystem. Two anonymous online marketplaces were crawled across 2020 and 2021, White House Market (WHM), and Empire Market. This data was extracted and examined to identify trends within both the international online market and the online market specifically for Australian documents, both of which have been relatively underexplored in the online space. To help illuminate the features of the market, the types of documents for sale, supply and demand trends, and trafficking flows along with vendor-related trends (e.g. product diversification and presence across markets) were examined. Each market was examined individually and then, where possible, comparisons were drawn to gain a more holistic understanding of the online fraudulent document market, with a specific focus on Australian products. Results indicate that, while the fraudulent document portion of the market is small, it is diverse, with numerous different identity-related products for sale, the most common being driver's licences from the United States (U.S.) and Australia, with digital documents dominating the whole marketplace. Overall, the most popular U.S. products we

The manufacture and distribution of fraudulent identity documents (IDs) is a pervasive and prolific crime problem, enabling the activities of organized crime networks and terrorist cells. As reactive policing methods are ill-equipped to handle the transversal and repetitive nature of document fraud, in 2012 Baechler et al. suggested a complementary method that uses the systematic profiling and comparison of fraudulent IDs to identify those produced by the same source. While this method has been successful in Europe, it is yet to be implemented worldwide, and there is currently little known about the Australian fraudulent document climate. In this pilot study, 43 fraudulent IDs from Sydney-based New South Wales police stations were examined. Adapting the method used in Europe, these documents were imaged, and their visual characteristics were extracted before being organized into an excel database and manually compared. The characteristics chosen are fundamentally linked to the manufacturing process, including the printing methods and replication of security features. Of the documents examined 88% were linked to at least one other document, and five series emerged. These results suggest that the Australian document market may be structured, and that there may be prolific offenders operating at its core, much like in Europe.

The use of plastics is extremely prevalent in society, with most individuals likely to handle several plastic items per day. It is therefore not surprising that many exhibits recovered from the scene of a crime are plastics, which are processed and examined for traces such as fingermarks. Societal trends have been pushing towards more environmentally friendly products with alternatives to traditional disposable plastics becoming increasingly available. These alternate plastics have different chemical compositions and physical properties, which may impact fingermark development for these substrates. As most detection techniques are known to be substrate-dependent, it is crucial to review current methods and procedures to examine how effective they are on new materials. The aim of this research was to assess a range of fingermark detection techniques on biodegradable plastics and provide recommendations for the preferred technique. First, the prevalence of these materials in the Australian market was evaluated. Over 40 different plastics obtained within the Sydney area were then divided into six broad categories using consumer information in combination with ATR-FTIR spectroscopy analysis. Following this, selected plastics from each category were used as substrates for the fingermark development study. In total, 6480 fingermark specimens were collected as split marks, to form 2160 fingermark comparisons. Each substrate was then developed with four fingermark detection techniques suitable for plastic substrates: cyanoacrylate (CA) fuming, vacuum metal deposition (VMD), powder suspensions (PS), and single metal deposition (SMD). SMD resulted in the most consistent development method across all tested substrates. VMD was able to successfully develop fingermarks on polyethylene-based plastics, but led to poorer results on alternative plastics, while CA fuming and PS were notably more dependent on the surface texture. This research was successful in confirming that biodegr

Fingermark detection research aims to improve the quantity and quality of fingermarks detected through the development of novel techniques. Subsequently, there is a need to evaluate these methods to determine the quality of the developed mark. Since the 1980's there has been a significant number of publications, which utilise a variety of different quality assessment methods. The introduction of common practice methods from the International Fingerprint Research Group (IFRG) aimed to implement a more standardised approach. Although these schemes are recommended as common practice, they are only guidelines. Consequentially, there is currently no universally accepted method to evaluate the enhancement techniques implemented in research. Therefore, this study aimed to collate and analyse the published protocols being used within fingermark detection research in order to better understand their application and how research is currently analysing and interpreting fingermark quality. This study comprised of manual and automatic searches of over 2000 published papers within the fingermark detection area. After thorough analysis of the articles, 396 published papers were found to have used a scale within the years spanning 1998-2022. The number of publications that report the use of a scale to assess quality for fingermark detection research has considerably increased over the last decade. However, whilst the number of publications utilising scales has increased, it is not proportional to the number of papers using the IFRG scales. The choice of scale is often institution specific and even more specific to their location. There are also numerous different adaptations of the IFRG recommended scales, as well as novel scales, which do not associate with the IFRG recommended versions being introduced the more research continues to grow. One such reason for this is investigated here, as different quality parameters are utilised within each individual scale. There is underreprese

Powder suspensions (PS) are a fingermark development technique made up of a mixture of an insoluble powder and surfactant solution. In the UK, carbon-based PS is used operationally on adhesive surfaces while iron oxide-based PS is used on flexible plastics. In NSW, Australia, only carbon-based suspensions are used due to a lack of research using iron oxide PS in an Australian context. In this research, a range of iron oxide powders and surfactant types were tested to optimise two iron oxide formulations. General observations found that thinner suspensions improved the ease of use in this technique while slightly improving the quality of developed fingermarks. The first optimised formulation involved a magnetic iron-oxide from Fisher Scientific mixed with a dilute Triton X-100 surfactant, and the other an iron-oxide nanopowder from Sigma Aldrich mixed with a 4% Tween 20 solution. The two formulations were then compared with a pre-mixed carbon-based PS, Wet Powder. This comparison showed that the effectiveness of each formulation is heavily dependent on substrate type. Both formulations had issues with heavy background staining on different kinds of surfaces. However, Wet Powder was shown to be the most consistently effective fingermark detection technique overall, especially on adhesive tapes. Despite this, iron-oxide PS were still a highly effective fingermark development technique, notably on plastic surfaces.

This study is the second part of a larger body of research dedicated to the production of synthetic secretions and the use of an inkjet printer to deposit realistic artificial fingermarks. An artificial emulsion combining eccrine and sebaceous compounds, which was described and tested in the first part of this research, was used as it showed a promising compatibility with common detection techniques. An inkjet printer was modified to print the emulsion on two different substrates: paper (porous) and acetate (non-porous). After optimisation of the printing parameters, multiple fingermarks were printed and processed with a range of standalone detection techniques: 1,2-indanedione-zinc, ninhydrin, Oil Red O, and physical developer on paper, and cyanoacrylate fuming, rhodamine 6G, gold/zinc vacuum metal deposition, and silver black powder on acetate. The detection techniques were also applied in sequence, which is considered one of the biggest advantages of the emulsion over simpler amino acid mixtures that are usable with amino acid reagents only. Natural fingermarks deposited by a single donor were processed with the same techniques for comparison. The effect of water immersion was also investigated, where fingermarks printed on paper were immersed in water for 15 min, before being processed with 1,2-indanedione-zinc and Oil Red O. The results showed that realistic-looking fingermarks could be printed on paper and that printing on acetate was also possible albeit of lower quality due to the nature of the substrate. The artificial fingermarks were successfully enhanced by all the detection techniques tested, at the notable exception of physical developer. The results obtained were very similar to what is generally observed with real fingermarks, and it was observed that the impact of water immersion on the artificial fingermarks was comparable as well. These findings open new perspectives for the development of multi-target quality control test strips or for the standa

Investigations into the application of carboxyl-functionalised silicon oxide nanoparticles doped with a ruthenium complex (RuBpy-doped CES-SiO2 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-SiO2 NPs for fingermark detection, the versatility and overall practicality of the optimised SiO2 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.

This paper reports the synthesis of high-quality upconverting nanoparticles (UCNPs) - sodium yttrium tetrafluoride doped with ytterbium and erbium (NaYF4: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.

Fingerprint powders remain one of the most common detection techniques used at the crime scene. However, powder efficiency and contrast can be hindered when applied to highly patterned backgrounds. This problem can be overcome using powders that are luminescent in the near-infrared (NIR) region of the electromagnetic spectrum. Despite being commercially available, those powders have been the focus of only a small number of studies, limited to a few substrates or donors. Their performance and advantages over common techniques are still to be thoroughly investigated. This study aims at assessing the performances of two NIR powder (fpNATURAL 1® and Universal Powder an in-house developed powder) against two conventional powders, a black and a luminescent powder (Sirchie Black, GREENcharge™) under various optical conditions (white light, visible luminescence and NIR luminescence). The powders were compared on four substrates using fingermarks of four different ages from five donors. A total 900 fingermarks were collected for each pairwise comparison. NIR imaging provided good background suppression and a high contrast, however it was shown that conventional powders remained the most effective powdering methods on the substrates tested as sufficient contrast could be achieved under white light or in luminescent mode in the visible region. The results showed that Universal Powder performed similarly to conventional powders, but poor performances were obtained on most substrates with fpNATURAL 1®. Based on the results obtained, it is recommended to use NIR powders only on substrates or conditions where traditional powders are known to perform poorly.

Fingermark variability is a critical parameter. To mitigate the effects of this variability, synthetic secretions in the form of simple mixtures of target compounds found in eccrine sweat have been described in the literature, but they are usually reactive towards only a minimal range of detection techniques. If this approach is acceptable for the production of single-technique test strips, such artificial secretions cannot be considered as reliable fingermark simulants because they do not reproduce the complex matrix that makes up real secretions. Research has shown that sebaceous and eccrine compounds are probably present simultaneously in fingermark residue in the form of an emulsion. This paper is the first part of a research project that aims at producing realistic artificial fingermarks containing an extensive range of eccrine and sebaceous compounds. This first study aimed to reproduce and compare two synthetic fingermark residues formulations and assess their potential to be used as fingermark simulants. Spot tests of the artificial secretions were deposited on paper substrates, and their reactivity with four common detection techniques was tested: 1,2-indanedione-zinc, ninhydrin, oil red O, and physical developer. Both formulations showed very good results when processed with the two amino acid reagents, as well as oil red O, and no obvious differences were observed between the two versions. The results obtained with the physical developer were inconsistent and demonstrated that the fundamental working principle of physical developer needs to be further understood. The results were extremely promising as they showed the potential of such reproducible artificial secretions to be used to assess an extensive range of detection techniques, which would be highly beneficial to guarantee better research and quality control in fingermark detection. The use of spot tests to deposit the simulant was shown to be unreliable and a more controllable and reproducible depo

Among the different types of nanoparticles (NPs) proposed for fingermark detection, silicon oxide nanoparticles (SiO2 NPs) are arguably the most promising due to their unique characteristics. In this study, carboxyl-functionalised SiO2 NPs doped with luminescent ruthenium complex-RuBpy-doped CES-SiO2 NPs-were further studied to investigate their effectiveness for latent fingermark detection. A modified version of the functionalised SiO2 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-SiO2 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 SiO2 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.

© 2020 This paper reports the synthesis of high-quality upconverter nanoparticles (UCNPs) – sodium yttrium tetrafluoride doped with ytterbium and erbium (NaYF4:Yb,Er) with a silica shell and capped with carboxyl functional groups. The effect of different synthesis methods on the silica capping has been studied in detail. The main goal of this research was to design tailor-made UCNPs for fingermark detection and to validate a NP-based detection technique that is user-friendly, cost-effective and can be implemented in routine practice by law enforcement agencies. UCNP powders and solutions were used as a proof-of-concept to detect latent fingermarks on an aluminium foil substrate. This study not only highlights the potential use of UCNPs as a fingermark detection method but also identifies a number of shortfalls in its application that need to be addressed before such an approach could be implemented as a valid detection technique.

© 2018 Elsevier B.V. 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.

© 2019, © 2019 Australian Academy of Forensic Sciences. A total of 514 individuals from the Sydney area volunteered their fingerprint scans for analysis. The prints were classified using the eight main patterns of the National Crime Information Centre system. Additional information from the volunteers, including sex and ancestry, was documented. Using this information, the frequencies of each pattern for each biogeographical ancestry (BGA) group and sex were calculated. Trends showed that males and females have a difference in the frequency of plain arches; none of the other patterns showed clear differentiation. BGA trends showed that European and Middle Eastern groups had more similar frequencies for the less common patterns (plain arch, tented arch, radial loop, central pocket loop whorl and double loop whorl). Whereas for the common patterns of ulnar loop and plain whorl, European and South Asian groups were more similar in frequency.