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1.
Forensic Sci Int ; 358: 112019, 2024 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-38599146

RESUMO

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.

2.
Forensic Sci Int ; 350: 111804, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37536074

RESUMO

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 standardisation of proficiency testing and interlaboratory collaborative exercises where ground truth is crucial to guarantee comparable results and objective assessment.


Assuntos
Dermatoglifia , Zinco , Emulsões , Indicadores e Reagentes , Acetatos , Aminoácidos
3.
Forensic Sci Int ; 350: 111783, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37453206

RESUMO

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 underrepresentation of these quality parameters within some of the IFRG scales, in particular the Centre for Applied Science and Technology (CAST) scale. This correlates to the considerable number of tailored approaches as authors are forced to add these parameters within the descriptions. Until there is an introduction of clear guidelines surrounding all areas of fingermark quality, from definition to parameters chosen within phases, the research area will continue to face such issues. This article recommends areas of potential study, whilst also recommending procedures that may be employed to alleviate some of the issues seen with fingermark quality evaluation.


Assuntos
Dermatoglifia , Tecnologia
4.
Forensic Sci Int ; 347: 111685, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37062139

RESUMO

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.

5.
Forensic Sci Int ; 344: 111571, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36702004

RESUMO

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 biodegradable plastics do in fact have an impact on fingermark development techniques commonly applied on traditional plastics and recommendations have been formed to aid in operational contexts to improve the potential to recover latent fingermarks from biodegradable plastics.


Assuntos
Plásticos Biodegradáveis , Dermatoglifia , Humanos , Austrália , Cianoacrilatos , Polietilenos , Pós
6.
Forensic Sci Int ; 335: 111275, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35334410

RESUMO

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.


Assuntos
Nanopartículas , Dióxido de Silício , Alumínio , Cianoacrilatos , Dermatoglifia
7.
Forensic Sci Int ; 331: 111166, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34973483

RESUMO

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 deposition method using an inkjet printer will be presented in the second part of this research.


Assuntos
Dermatoglifia , Ninidrina , Indicadores e Reagentes , Suor , Zinco
8.
Forensic Sci Int ; 328: 111023, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34600266

RESUMO

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.


Assuntos
Luminescência , Dermatoglifia , Luz , Pós , Espectroscopia de Luz Próxima ao Infravermelho
9.
Forensic Sci Int ; 326: 110915, 2021 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-34343943

RESUMO

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.

10.
Forensic Sci Int ; 315: 110442, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32777689

RESUMO

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.


Assuntos
Dermatoglifia , Nanopartículas , Dióxido de Silício , Cianoacrilatos , Feminino , Corantes Fluorescentes , Humanos , Masculino , Rodaminas , Fatores de Tempo , Volatilização
11.
Forensic Sci Int ; 314: 110411, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32688262

RESUMO

Fingermark detection is in constant evolution, with new techniques being developed and existing ones being continuously optimised. Recently, researchers have begun to express interest in artificial fingermark secretions to overcome the issues arising from the variability of fingermark composition. Some of these artificial secretions have started to appear on the market in the form of pads that can be used to deposit fingermarks with a known and controlled composition. This study aimed at assessing the reliability of three commercially-available pads by comparing the results to those obtained by real fingermarks, using six detection techniques (1,2-indanedione/zinc, ninhydrin, cyanoacrylate followed by rhodamine 6G staining, gold/zinc vacuum metal deposition, and physical developer) on five substrate types (copy and recycled paper, acetate, glass, and glossy paper). The results showed that the artificial fingermarks deposited with these pads reacted in an unreliable way, notably when treated with complex detection techniques such as Physical Developer. Further, the high concentration of some of the target compounds found in the artificial secretion led to an over performance of some detection techniques, which could mislead the operator to overestimating the efficiency of a given method. The resulting artificial fingermarks are considered too dissimilar to real fingermarks to be used as quality control standards and better simulants need to be found for a more efficient and realistic control of the variability.


Assuntos
Dermatoglifia , Medicina Legal/instrumentação , Cianoacrilatos , Técnicas Eletroquímicas , Ouro , Humanos , Indanos , Indicadores e Reagentes , Ninidrina , Reprodutibilidade dos Testes , Rodaminas , Coloração e Rotulagem , Zinco
12.
Forensic Sci Int ; 298: 372-383, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30928777

RESUMO

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 (SiO2 NPs). In a recent optimisation of the technique, the use of carboxyl-functionalised SiO2 NPs doped with luminescent ruthenium complex was proposed as a breakthrough for latent fingermark detection. In this study, the aforementioned functionalised SiO2 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 SiO2 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.

13.
Forensic Sci Int ; 294: 103-112, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30500490

RESUMO

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.


Assuntos
Dermatoglifia , Ciências Forenses/métodos , Coloide de Ouro , Humanos , Imersão , Indanos , Indicadores e Reagentes , Ninidrina , Porosidade , Prata , Zinco
14.
Forensic Sci Int ; 291: 83-93, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30172095

RESUMO

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.


Assuntos
Dermatoglifia , Estruturas Metalorgânicas , Sangue , Estudos de Viabilidade , Medicina Legal/métodos , Humanos , Luminescência , Sêmen , Propriedades de Superfície , Fatores de Tempo
15.
Forensic Sci Int ; 289: 381-389, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29960948

RESUMO

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.


Assuntos
Dermatoglifia , Cianoacrilatos , Humanos , Indanos , Porosidade , Rodaminas , Coloração e Rotulagem , Propriedades de Superfície , Fatores de Tempo
17.
Forensic Sci Int ; 286: 1-7, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29524741

RESUMO

Fingermarks can be exploited for both their ridge detail and touch DNA. One-step luminescent cyanoacrylate (CA) fuming techniques used for fingermark enhancement, such as PolyCyano UV (Foster+Freeman Ltd) and Lumicyano™ (Crime Science Technology), claim to be compatible with DNA analysis as they reduce the need for post-staining to increase contrast of the developed fingermark. The aim of this study was to determine the impact that these one-step luminescent cyanoacrylates have on DNA analysis and how they compare to conventional CA techniques. Four donors each deposited five sets of natural fingermarks, to which a known amount of washed saliva cells was dispensed onto half of each set of fingermarks. Each set was treated with either a conventional CA technique or a one-step luminescent CA technique prior to collection and processing of DNA, with one set left as a non-fumed control. It was found that DNA was still recoverable and detectable following each of the treatments. Lumicyano™ had a similar impact on DNA profiles as conventional CA fuming and with post-stain, however, the degradation effect of PolyCyano UV on DNA was greater than the conventional treatments. For quantities of DNA such as that from touch DNA, the use of PolyCyano UV to enhance fingermarks may impact subsequent DNA analysis by causing allele drop out at larger fragment sizes.


Assuntos
Cianoacrilatos , Impressões Digitais de DNA , DNA/isolamento & purificação , Dermatoglifia , Substâncias Luminescentes , Volatilização , Degradação Necrótica do DNA , Humanos , Reação em Cadeia da Polimerase
18.
Data Brief ; 16: 1010-1024, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29322083

RESUMO

The data presented here is related to the article titled, "Using handwriting to infer a writer's country of origin for forensic intelligence purposes" (Agius et al., 2017) [1]. This article reports original writer, spatial and construction characteristic data for thirty-seven English Australian writers and thirty-seven Vietnamese writers. All of these characteristics were coded and recorded in Microsoft Excel 2013 (version 15.31). The construction characteristics coded were only extracted from seven characters, which were: 'g', 'h', 'th', 'M', '0', '7' and '9'. The coded format of the writer, spatial and construction characteristics is made available in this Data in Brief in order to allow others to perform statistical analyses and modelling to investigate whether there is a relationship between the handwriting features and the nationality of the writer, and whether the two nationalities can be differentiated. Furthermore, to employ mathematical techniques that are capable of characterising the extracted features from each participant.

19.
Forensic Sci Int ; 282: 144-156, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29202337

RESUMO

Forensic science has traditionally focused the majority of its resources and objectives towards addressing Court-related questions. However, this view restricts the contribution of forensic science to one process and results in a loss of information as the investigative and intelligence roles are largely neglected. A forensic science discipline suffering from this imbalance is handwriting examination, which may be characterised as a time consuming and subjective process that is mostly carried out towards the end of the investigation for the purpose of judicial proceedings. Individual and habitual characteristics are the major handwriting features exploited, however alternate information concerning the author's native language could potentially be used as a key element in an intelligence framework. This research focussed on the detection of characteristics that differentiate Vietnamese and English Australian writers based on their English handwriting. The study began with the extraction of handwriting characteristics from the writing of people from the two populations. The data was analysed using a logistic regression model and a classification and regression tree (CRT). Each recognised four class characteristics that were capable of distinguishing between the two nationalities. The logistic regression and CRT models were both capable of correctly predicting 93% of cases. Their predictive capabilities were then tested and supported using blind exemplars in order to mirror casework settings. It appeared that when using their respective class characteristics, the two models were capable of differentiating English Australians from Vietnamese in the data set. This proof of concept research demonstrated the plausibility of exploiting this additional information from a handwriting trace and taking advantage of it in an intelligence-led framework.

20.
Sci Justice ; 57(5): 394-400, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28889870

RESUMO

Traditionally, forensic science has predominantly focused its resources and objectives on addressing court related questions. However, this view restricts the contribution of forensic science to one function and results in lost opportunities as investigative and intelligence roles are often overlooked. A change of perspective and expansion of the contributions of forensic science is required to take advantage of the benefits of abductive and inductive thought processes throughout the investigative and intelligence functions. One forensic discipline that has the potential to broaden its traditional focus is handwriting examination. Typically used in investigations that are focused on both criminal and civil cases, the examination procedure and outcome are time consuming and subjective, requiring a detailed study of the features of the handwriting in question. Traditionally, the major handwriting features exploited are characteristics that are often considered individual (or at least highly polymorphic) and habitual. However, handwriting can be considered as an information vector in an intelligence framework. One such example is the recognition of key elements related to the author's native language. This paper discusses the traditional method generally used around the world and proposes a theoretical approach to expand the application of handwriting examination towards gaining additional information for intelligence purposes. This concept will be designed and tested in a future research project.


Assuntos
Ciências Forenses/métodos , Escrita Manual , Humanos
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