Field-based detection of biological samples for forensic analysis: Established techniques, novel tools, and future innovations

Ultrasensitive determination of cobalt in single hair by capillary electrophoresis using chemiluminescence detector

Currently, analytical chemistry is more than simply its division into classical and instrumental. It is an interdisciplinary area that involves notions of biology, toxicology, statistics, computer science, and physics, among others. There are several areas of knowledge applied in the development of a chemical analysis, which is configured as all the processes necessary for the identification and quantification of the different components of a sample. When this sample is a trace material from a crime scene, analytical chemistry assumes a central role in the conversion of this sample into material evidence with legal value through consolidated and validated procedures, obtained by exhaustive investigative and methodological studies. The responsibility assumed is in the confidence of the result obtained, which will only be possible with the validation of the method. Although not all methods are perfect, a quantitative determination requires a precise and accurate methodology. Therefore, analytical chemistry is very important to forensic chemistry. Material evidence has a great influence on a trial because it is clothed in technical characteristics, and the expectation is that it will help to unequivocally clarify the truth of the facts. It is this expectation that makes the work of the analytical chemist so important in conducting an analytical procedure for forensic purposes. The result obtained may or may not incriminate someone. Another analytical challenge in forensic analysis is the collection and preparation of a sample that has a criminal trace profile. Such procedures should preserve as much of the criminal evidence as possible. At a crime scene, several samples can be considered evidence: soils, fibers, glass, gunshot residues, explosives, among others. Locard's principle of exchange states that whenever two objects come into contact, an exchange of materials occurs between them and, thus, a connection is established between the suspect and the crime scene or between the suspect and the victim based on the transfer of fragments of the materials. Once again, analytical rigor will play a relevant role in the preservation and experimental conduct of the traces. A failure in the analytical procedure may make it impossible to use a trace as material evidence in a court of law, jeopardizing its use in the conviction of the judge or jury. It is up to the forensic analysts to provide a result with credibility and legal security, i.e., to rigorously follow the analytical protocols. Forensic research is dynamic. One example is the demand for analytical methods that encompass the wide variety of newly emerging psychoactive substances (NPS), formerly known as "designer drugs", which must continually be detected and catalogued. In the Interview in this volume, Dr. Barry Logan tells us about this challenge in his career. I want to register my special thanks to Prof. Dr. Bruno Martinis from the Department of Chemistry of the Faculty of Philosophy, Sciences and Letters of Ribeirão Preto, University of São Paulo (DQ-FFCLRP-USP) of -, who mediated and made possible the interview for BrJAC of one of the most prominent scientists in the area. In his Point of View, Federal Criminal Expert Marcus Andrade tells us about the complexity of forensic chemical analysis of works of art. The analysis of the surface of a painting requires, besides the historical study of the piece, the physical-chemical characterization of its components through an interesting combination of non-destructive analytical techniques such as microscopy, X-ray fluorescence, infrared spectroscopy, among others, which are powerful tools in the process of authenticating a work of art. Nevertheless, the art market, due to the high added value, has attracted organized crime in money laundering in cases of active and passive corruption. Prof. Dr. Jesus Antônio Velho, Federal Criminal Expert and lecturer at the DQ-FFCLRP-USP, addresses the new trends in analytical chemistry for the examination and interpretation of traces of crimes: the determination of the origin of seized drugs (chemical profile), the investigation of document fraud, and the analysis of the evaluation of works of art. Professor Jesus' letter is the result of his long experience in the field and his exceptional insight into the forensic sciences. The author of several books in the field, his text is a gift to us all. We hope readers will enjoy this special edition of BrJAC. Forensic professionals, students, professors, and researchers seek to contribute to criminal justice more broadly through tireless dedication. When we apply forensic analytical chemistry to a crime scene, more than an expert report, we give voice to the victims, who, through their traces, reveal to us the truth of the facts.

Vehicle tire tread pattern is an important part of vehicle tire and also an important object concerned by the police workers who want to deduce or identify the suspected vehicle tire through the tire pattern impression left on the crime scene, which is routinely reflected by tire pattern impression on the surface tire rolled through. In this paper, the characteristics of vehicle tire pattern and its application in forensic science was analyzed and summarized in accordance with cases, based on the analysis of the process of production and using. The research indicated that the tire pattern not only has type characteristics corresponding to vehicle type, but also may have some new individual characteristics in the process of production and using in special condition. The morphological characteristics of tire pattern can be reflected more or less by the tire impression which left on road, clothes or body skin. With the development of trace extraction and enhancement technology, the morphological characteristics of tire pattern in tire impression will be used to deduce vehicle type or identify the suspected vehicle tire, which will play an important role in forensic evidence.

Today, cloud computing has developed a transformative model for the organization, business, governments that brings huge potentials and turn into popular for pay as you go, on-demand service, scalability and efficient services. However, cloud computing has made the concern for forensic data because of the architecture of cloud system is not measured appropriately. Due to the distributed nature of the cloud system, many aspects relating to the forensic investigation such as data collection, data storage, crime target, data violation are difficult to achieve. Investigating the incidents in the cloud environment is a challenging task because the forensics investigator still needs to relay on the third party such as cloud service provider for performing their investigation tasks. It makes the overall forensic process difficult to complete with a duration and presented it to the court. Recently, there are some cloud forensics studies to address the challenges such as evidence collection, data acquisition, identifying the incidents and so on. However, still, there is a research gap in terms of consistency of analysing forensic evidence from distributed environment and methodology to analyse the forensic data in the cloud. This thesis contributes towards the direction of addressing the research gaps. In particular, this work proposes a forensic investigation framework CeFF: A framework for forensics enabled cloud investigation to investigate evidence in the cloud computing environment. The framework includes a set of concepts from organisational, technical and legal perspectives, which gives a holistic view of analysing cybercrime from organisation context where the crime has occurred through technical context and legal impact. The CeFF also includes a systematic process that uses the concept for performing the investigation. The cloud-enabled forensics framework meets all the forensics related requirement such as data collection, examination, presents the report, and identifies the potential risks that can consider while investigating the evidence in the cloud-computing environment. Finally, the proposed CeFF is applied to a real-life example to validate its applicability. The result shows that CeFF supports analysing the forensic data for a crime occurred in cloud-based system in a systematic way.

This book by Ian Burney and Neil Pemberton identifies and explains the origins of modern crime scene investigation (CSI) as a medico-scientific system with networks of institutions, concepts and practices focused on the crime scene as a distinct space ‘bounded conceptually and operationally by explicit rules of practice’ (p. 3). Using homicide as a lens through which to examine this process, the book sets up an important distinction between two paradigms of crime investigation and the sites in which they are performed. Forensic pathology, common since the nineteenth century, studies bodies in a mortuary. But forensic science has a more recent pedigree and a wider sphere of operation: it is concerned with the things found on or around a body (known as trace evidence) and practised at two locations, the crime scene and the laboratory, usually by teams rather than individuals. But forensic pathology and science interact at these three sites and in a fourth, the courtroom; there is thus no simple story of substitution of one for the other. Instead, by the 1950s, conceptual, technical and institutional changes had resulted in the integration of the lone inter-war pathologist into the emergent procedures of CSI.

In Chapter 1 of this edited collection of new essays Paul Roberts surveys the current forensic science landscape, from the perspective of an English legal scholar. His primary objective is to ‘make sense’ of this massive, diverse, fragmented and somewhat contested terrain. Having listed no fewer than twenty different ways in which forensic science evidence has been viewed as problematic, Roberts proceeds to elucidate the epistemological grounds for rational reliance on expert evidence and to consider the structural properties and resilience of the regulatory and procedural frameworks which govern this type of evidence in England and Wales. He then turns his attention to the ‘intellectual resources’ of ‘forensic science’, understood expansively to include models of evidential interpretation and frameworks for structuring inferential reasoning (including ‘Bayesian’ approaches). Roberts stresses the complexity and dynamism of the regulatory challenge of guaranteeing the reliability of forensic science evidence. Legal scholars have tended to focuses on doctrinal issues, especially the task of formulating suitable evidentiary rules to regulate the admissibility of forensic science evidence in contested trials. Further reflection quickly demonstrates that admissibility is not the only doctrinal question posed by forensic science (and other expert) evidence; and moreover, doctrinal questions barely scratch the surface of the broader and deeper institutional, scientific, socio-legal and jurisprudential ‘problematic’ of forensic science.

In forensic DNA analysis, salivary traces at crime scenes are a promising way to identify a person. However, crime scenes are oftentimes investigated a while after the crime and recovered samples might have been degraded leading to poor PCR amplification. Probably due to decomposition and negative visual impression of spoiled food, bite mark samples make up only a small part of our casework routine. In this study, bite marks on apples and chocolate bars as well as on an inert surface (microscope slide) were stored up to 3weeks indoors and outdoors during different seasons and analyzed for amylase activity and DNA quantity and quality. The results underlined the stability of human nuclear DNA not only on inert but also on biological surfaces and their forensic usefulness even when bite marks are stored 21days under adverse but realistic conditions at a crime scene. Overall, amylase activity as well as DNA quantity decreased over time depending on storage environment with a certain inter- and intrapersonal variation. But amylase activity testing was not found to be an appropriate screening tool for further analysis. Apple bite marks resulted in generally higher DNA amounts than chocolate bars and microscope slides. Although mold reduced the DNA quantity, complete STR profiles could be analyzed. High air humidity and cold temperatures were found to act preservative on raw food with high water content but caused loss of information over time for smooth inert surfaces and hygroscopic foods like sweets. Many factors are involved in the stability of DNA in bite marks and its resulting quality and quantity available for an STR analysis. However, since there was a substantial proportion of informative STR profiles even from bite marks stored for 21days, the results encourage the analysis of those even if their visual appearance seems unfavorable.

Source identification of human biological materials in crime scene plays an important role in reconstructing the crime process. Searching specific genetic markers to identify the source of different human biological materials is the emphasis and difficulty of the research work of legal medical experts in recent years. This paper reviews the genetic markers which are used for identifying the source of human biological materials and studied widely, such as DNA methylation, mRNA, microRNA, microflora and protein, etc. By comparing the principles and methods of source identification of human biological materials using different kinds of genetic markers, different source of human biological material owns suitable marker types and can be identified by detecting single genetic marker or combined multiple genetic markers. Though there is no uniform standard and method for identifying the source of human biological materials in forensic laboratories at present, the research and development of a series of mature and reliable methods for distinguishing different human biological materials play the role as forensic evidence which will be the future development direction.

This chapter examines issues arising from cases that turn on forensic and expert evidence, focusing on how the Criminal Cases Review Commission investigates such applications and makes its decisions. Drawing on a sample of sixty-one cases involving forty-two applicants, the chapter shows how the Commission makes decisions in cases that ‘turn on’ forensic science and expert testimony. It also considers the influence of developments in the ‘surround’ of the Commission and how the surround affects the Commission's decision field — the broad setting within which decision-making at the Commission takes place. Finally, it analyses the role of decision frames in the Commission's decision-making on forensic and expert evidence cases, noting that such frames are characterised by uncertainty and even anxiety. Concerns about the interpretation and presentation of forensic evidence at trial are discussed, along with the legal and narrative frames of decision-making in forensic and expert evidence cases.

The omnipresence of images within contemporary society has impacted on how visual evidence is perceived and presented within the criminal justice system. Currently there are no universally recognised methodological principles or practices established that allow robust and reliable forensic evaluation of images. The objective of this research was to elucidate critical conceptual and pragmatic principles for the development of a methodological framework aimed to support the forensic photointerpretation of photographic evidence. Using a mixed method research design, this project explored three methodological approaches, namely criteria, comparative and reconstructive based photointerpretation methods. Case studies, literary reflection, experimentation and evidence-based discussion were employed to unpack and investigate nuanced and complex concepts, values and principles required for consideration when using photographs as sources of evidence. Six key principles were derived from the values elucidated in response to each investigated approach. These principles consisted of methodology; objectivity; suitability; verifiability; specialised knowledge and error. The model developed by this research promotes transparency and clarity towards the process of photographic interpretation as forensic evidence presented within the criminal justice system.

Two experimental studies examined the effect of opposing expert testimony on perceptions of the reliability of unvalidated forensic evidence (anthropometric facial comparison). In the first study a...

Context: Consumption of synthetic drugs had increased in recent years, used as a recreational drug by young people who presume that consumption of this drug is harmless for health; however clinical studies have shown that this stimulant and its metabolites are toxic. Due to these reasons, chemical analysis of this illicit drug is crucial from the points of view of occupational medicine, toxicology, and law enforcement with the aim of pursuit the traffic of illegal drug. Aims: Implement and fully validate a rapid and simple method for detection and quantitation of MDMA by High-Performance Thin Layer Chromatography in seized samples. Methods: With the implemented method was analyzed 12 positive samples seized by Chilean police, to found the concentration of MDMA in ecstasy tablets. Results: The method was fully validated, the linearity of the method was evaluated by the calibration curve between 51.0 – 510.0 µg/band (R2 0.9977); limit of detection was 12.1 µg per band, and limit of quantitation was 36.8 µg per band. The precision of the method (RSD) was lower than 5.0%. Accuracy was evaluated by determination of the percentage of MDMA recovered by the assay (99.13%), and relative Uncertainty was 6.66%. With this method, it was analyzed real seized samples of MDMA, results showed that all samples contained MDMA and concentration was between 18.15 – 59.84 % w/w. Conclusions: The method is selective, sensitive, and specific, with possible application in forensic analysis. To the best of our knowledge, this is the first report about concentration of MDMA in ecstasy pills in Chile.

Human bone marrow as a tissue in post-mortem identification and determination of psychoactive Substances-Screening methodology.

Science, Technology, or the Examiner Experience: What Influences Jurors' Judgments About Forensic Science Testimony?

Climate change causes great impact on ambient temperatures. In forensic pathology, temperature has always been an important variable to determine numerous thanatodiagnostic and thanatochronological parameters, as crucial elements to make scientifically valid forensic conclusions. The aim of this work is to describe the impact that climate change is having on the forensic science and crime scene analysis. A literature review was carried out on the search engines Pubmed, Scopus and Google Scholar. The keywords "climate change" AND "forensic" were used. Climate change is having a significant impact on forensic science in several areas. Among these it is necessary to consider: 1) global warming and crime scenes: high temperature of the planet causes frequent extreme meteorological events in multiple periods of the year; 2) Relationship between climate and PMI (Post Mortem Interval): Temperature influences the rapidity of putrefaction; 3) Relationship between climate and fauna: global warming is influencing the geographical distribution of animal species, with real migrations of species. Fauna has a decisive impact in the forensic field (as in the case of entomology) creating new models of animal-cadaver interaction; 4) Relationship between climate and forensic botany: Climate change influences the flowering and fruiting times of plants, impacting knowledge on botany used in the forensic field. It is essential to adopt prevention measures to address the emerging challenges.