Contrast Enhancement for the Recovery of Obliterated Serial Numbers in Different Polymers by Correlated Raman Imaging of Strain, Phonon Lifetime, and Strain-Induced Anisotropy.

In the field of forensic science, we have recently introduced Raman imaging as a promising nondestructive technique to efficiently recover obliterated serial numbers in polycarbonate. The present study is extending the investigation toward different polymers for the reconstruction of abraded information by Raman spectroscopy. Samples of polyethylene, nylon, and nylatron, which are mainly used in items such as firearms, banknotes, and package materials, are investigated by monitoring the vibrational modes which are most susceptible to peak shifts and changes in the full width at half-maximum (fwhm) and peak intensity ratios. In all cases, the most affected peak depends on the polymer's 3D structure and displays a ∼1 cm-1 shift and a broadening above ∼2 cm-1, as well as a relative intensity change of over 50%, more than enough for a successful recovery through confocal imaging. Depending on the polymer's structural arrangement, any of the three contributions prevails for the strongest contrast. The propagation of the plastic deformations is mainly affected by the Young's modulus of the material, due to a change in its elasticity. The shift, the width, and the relative intensity of the Raman peaks being three independent parameters, they can be correlated to enhance the contrast and thus to accelerate the image acquisition or to enhance statistical significance.

Reconstruction of Obliterated Characters in Polycarbonate through Spectral Imaging.

In forensic sciences, there is an increasing demand for nondestructive and reliable methods to retrieve obliterated information in polymers. This study demonstrates a case study for the potential of Raman spectroscopy to reconstruct abraded serial numbers. Residual strain and local variations in the structural arrangement are nondestructively imaged through peak shifts and variations of the full width at half-maximum of specific Raman lines, respectively. We qualitatively validate our approach by successfully recovering an obliterated letter stamped with a pressure of ∼170 MPa in a polycarbonate sample, with a subsequent quantitative statistical analysis. The detection threshold is estimated from the propagation depth of plastic deformations to a value of ∼750-800 µm, substantially larger than typical obliteration depths, 200 µm in our case for an initial profile depth of 120 µm.

Towards a forensic semiotics.

For years, forensic science has been criticized for its lack of scientific foundations, explaining its methodological drawbacks. Notwithstanding recommendations to upgrade quality management and counter cognitive biases, the ontology of the trace and the very nature of forensic science amplified by its decision context is rarely invoked as sources of inescapable errors. Understanding what (forensic) science is could even reconcile the prescriptive approach and the descriptive cognitive reality, through an unexplored pathway, Peirce's semiotics. The implementation of a semiotic line of arguments could concur to the transparency of scientific opinions for security and justice purposes, with rich potentialities in sight.

Intersection of CBRN, military forensic science, and counterterrorism.

The wars in Iraq and Afghanistan required that forensic science was used beyond the traditional law enforcement and criminal justice goals and applied to military operations. The 9/11 terror attacks in the United States (US) inspired further attacks in the Western World and highlighted the importance of national and international intelligence sharing for counterterrorism operations. Following the 9/11 attacks, anthrax was disseminated in the US mail system, demonstrating a successful modern use of biological agents. As a result, nations enhanced their Chemical, Biological, Radiological and Nuclear (CBRN) capabilities to prevent, prepare, respond, and recover from CBRN attacks but in the last decade, there has been a decrease in capabilities across military forensic science, counterterrorism, and CBRN. Recent changes in the global and strategic environment such as, the war in the Ukraine, the threat of grey zone conflicts (below the threshold of war) such as the conflict in the Middle East, and strategic competition, indicates international, national, state and local CBRN capabilities need to be reinvigorated in a world under digital transformations. There is a need for a harmonized approach to enhance the integration of military, law enforcement, and CBRN operations to support decision-making. In this paper, we look back to where we have come from and where we are now to make recommendations on where to from here for military forensic science and counterterrorism, including CBRN which intersects both of these systems.

The use of mantrailing dogs in police and judicial context, future directions, limits and possibilities - A law review.

The extraordinary capabilities of the canine nose are increasingly being used by law enforcement agencies in many countries to solve and reconstruct crimes. As a result, this type of forensic evidence can be and is still being challenged in the courts. So far, only a few publications have addressed the jurisprudence concerning mantrailing. We provide an overview of the jurisprudence in Germany and the USA, as well as insights from France. Relevant databases were searched, and 201 verdicts from Germany and 801 verdicts from the USA were analyzed. As a result, 16 published verdicts on the topic of mantrailing were found for Germany, and 44 verdicts since 2010 were found for the USA. The use of mantrailers and human scent discrimination dogs is employed in the investigative process in all three countries. The results derived from these methods are admissible as evidence in court, albeit not as sole evidence.

Why teach crime scene management to forensic university students?

Despite enhanced forensic collaborations between law enforcement agencies and universities, crime scene management remains a domain seen more as technical than scientific, largely carried out by sworn police officers qualified as scene of crime officers (SOCOs), confining forensic graduates to specialized expertise fields. Under such circumstances, we must ask ourselves why and how do we provide a generalised dedicated course to academic pupils who are not primarily intended to join such teams, excepting sometimes to assist them on a specialized field (explosion, arson, etc.)? Currently in Quebec, forensic graduates cannot join crime scene units attached to police forces, mainly because of unions, which argue about the need to be an experienced police officer before qualifying for a crime scene course. Based on the operational experience of the author, who created the foundational graduate forensic programme in Quebec, Canada, this paper will explain why such an academic course is still of high importance, its rationale within an academic curriculum, its goal and its implementation. Challenges are still to be considered, but selected feedback from students who understood that the aim of this course is distinct from their formal support disciplines, encourage such an approach.

The Sydney declaration - Revisiting the essence of forensic science through its fundamental principles.

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.

Design and synthesis of transparent and flexible nanofibrillated cellulose films to replace petroleum-based polymers.

Nanofibrillated cellulose films have garnered attention due to their interesting proprieties such as transparency and high mechanical strength. However, they are brittle, very hydrophilic, which is decreasing their potential applications. We have successfully achieved a simple and effective chemical modification based on polymer grafting and through plasticizer additions to increase the performance of the films as well as to improve the compatibility within conventional polymer. A preliminary study shows the possibility of using this film as an interlayer in safety glazing and/or bulletproof glass with polyvinyl butyral (PVB). The modified NFC films displays high optical transmittance (93 %), increases tensile stretch and is more hydrophobic (83°). A higher flexibility was also achieved, as the film was greatly stretched and bended without cracking or breaking. The NFC / PVB composite has three times more elongation at break, 13 % more specific energy absorbed with a half-tensile stress compared to an interlayer of PVB.

Must the random man be unrelated? A lingering misconception in forensic genetics.

A nearly universal practice among forensic DNA scientists includes mentioning an unrelated person as the possible alternative source of a DNA stain, when one in fact refers to an unknown person. Hence, experts typically express their conclusions with statements like: "The probability of the DNA evidence is X times higher if the suspect is the source of the trace than if another person unrelated to the suspect is the source of the trace." Published forensic guidelines encourage such allusions to the unrelated person. However, as the authors show here, rational reasoning and population genetic principles do not require the conditioning of the evidential value on the unrelatedness between the unknown individual and the person of interest (e.g., a suspect). Surprisingly, this important semantic issue has been overlooked for decades, despite its potential to mislead the interpretation of DNA evidence by criminal justice system stakeholders.

Perspectives on the establishment of a canadian human taphonomic facility: The experience of REST[ES].

REST[ES] is the first Canadian human taphonomic facility (HTF) dedicated to research and training relating to human decomposition in a northern temperate climate. The following paper outlines the measures taken to successfully establish, open and operate this novel Canadian HTF with particular focus on: project team and partnerships, facility location, approvals and permits, infrastructure and social acceptability. It is intended that our experience of establishing REST[ES] may serve as an example to help others with the establishment of future HTFs, thus contributing to the expansion in the global accessibility to human decomposition research and training.

Management of crime scene units by Quebec police senior managers: Insight on forensic knowledge and understanding of key stakeholders.

What do policing leaders think and know of forensic science? Beyond crime scene investigators or detectives, how do police senior managers perceive the role, utility and limitations of forensic science? Very few empirical studies have addressed the issue. Forensic scientsts should be concerned about the perception that law enforcement senior managers have of their discipline for two reasons. First, strategic and financial decision-makers are obviously key players in the overall administration and provision of forensic science, either as a supervisor, money provider or as a customer. Second, literature has highlighted that other actors involved in forensic science underestimate the scope and possibilities offered by forensic science, hence limiting its exploitation and potential. Following interviews with 18 police senior managers from Quebec (Canada), this study shows that they generally restrict forensic science to a reactive discipline whose role and utility is to identify offenders and support the Court. This understanding of forensic science, like that of many others including a significant share of forensic scientists, differs from the perception of other police activities in modern law enforcement agencies where proactive action is sought. Considering these findings and the growing body of literature which calls for forensic science to connect more tightly with policing and security, we advocate a more extensive education of police leaders regarding the scope of forensic science.

Nature and place of crime scene management within forensic sciences.

This short paper presents the preliminary results of a recent study aimed at appreciating the relevant parameters required to qualify forensic science as a science through an epistemological analysis. The reader is invited to reflect upon references within a historical and logical framework which assert that forensic science is based upon two fundamental principles (those of Locard and Kirk). The basis of the assertion that forensic science is indeed a science should be appreciated not only on one epistemological criteria (as Popper's falsification raised by the Daubert hearing was), but also on the logical frameworks used by the individuals involved (investigator, expert witness and trier of fact) from the crime scene examination to the final interpretation of the evidence. Hence, it can be argued that the management of the crime scene should be integrated into the scientific way of thinking rather than remain as a technical discipline as recently suggested by Harrison.

Smartphone and Tablet Applications for Crime Scene Investigation: State of the Art, Typology, and Assessment Criteria.

The use of applications on mobile devices is gradually becoming a new norm in everyday life, and crime scene investigation is unlikely to escape this reality. The article assesses the current state of research and practices by means of literature reviews, semistructured interviews, and a survey conducted among crime scene investigators from Canada and Switzerland. Attempts at finding a particular strategy to guide the development, usage, and evaluation of applications that can assist crime scene investigation prove to be rather challenging. Therefore, the article proposes a typology for these applications, as well as criteria for evaluating their relevance, reliability, and answer to operational requirements. The study of five applications illustrates the evaluation process. Far away from the revolution announced by some stakeholders, it is required to pursue scientific and pragmatic research to set the theoretical foundations that will allow a significant contribution of applications to crime scene investigation.

The end of the (forensic science) world as we know it? The example of trace evidence.

The dominant conception of forensic science as a patchwork of disciplines primarily assisting the criminal justice system (i.e. forensics) is in crisis or at least shows a series of anomalies and serious limitations. In recent years, symptoms of the crisis have been discussed in a number of reports by various commentators, without a doubt epitomized by the 2009 report by the US National Academies of Sciences (NAS 2009 Strengthening forensic science in the United States: a path forward). Although needed, but viewed as the solution to these drawbacks, the almost generalized adoption of stricter business models in forensic science casework compounded with ever-increasing normative and compliance processes not only place additional pressures on a discipline that already appears in difficulty, but also induce more fragmentation of the different forensic science tasks, a tenet many times denounced by the same NAS report and other similar reviews. One may ask whether these issues are not simply the result of an unfit paradigm. If this is the case, the current problems faced by forensic science may indicate future significant changes for the discipline. To facilitate broader discussion this presentation focuses on trace evidence, an area that is seminal to forensic science both for epistemological and historical reasons. There is, however, little doubt that this area is currently under siege worldwide. Current and future challenges faced by trace evidence are discussed along with some possible answers. The current situation ultimately presents some significant opportunities to re-invent not only trace evidence but also forensic science. Ultimately, a distinctive, more robust and more reliable science may emerge through rethinking the forensics paradigm built on specialisms, revisiting fundamental forensic science principles and adapting them to the twenty-first century.

Computerized forensic assistance software (FAS 1.0) for training and standardized investigation in distributed and disconnected services.

As part of a European union (EU) support program in forensic science for the Palestinian police, a forensic assistance software was designed to respect the quality management of the anti-terrorism laboratory of the Palestinian police by the different forensic teams in the disconnected Palestinian cities. This tool not only proposes up-to-date detection and identification protocols for traces, explosives, drugs, GSR, biological samples, but also appeared to be a convenient support for forensic practice teaching.

The first successful use of a low stringency familial match in a French criminal investigation.

We describe how a very simple application of familial searching resolved a decade-old, high-profile rape/murder in France. This was the first use of familial searching in a criminal case using the French STR DNA database, which contains approximately 1,800,000 profiles. When an unknown forensic profile (18 loci) was searched against the French arrestee/offender database using CODIS configured for a low stringency search, a single low stringency match was identified. This profile was attributed to the father of the man suspected to be the source of the semen recovered from the murder victim Elodie Kulik. The identification was confirmed using Y-chromosome DNA from the putative father, an STR profile from the mother, and finally a tissue sample from the exhumed body of the man who left the semen. Because of this identification, the investigators are now pursuing possible co-conspirators.

The National DNA Data Bank of Canada: a Quebecer perspective.

The Canadian National DNA Database was created in 1998 and first used in the mid-2000. Under management by the RCMP, the National DNA Data Bank of Canada offers each year satisfactory reported statistics for its use and efficiency. Built on two indexes (convicted offenders and crime scene indexes), the database not only provides increasing matches to offenders or linked traces to the various police forces of the nation, but offers a memory repository for cold cases. Despite these achievements, the data bank is now facing new challenges that will inevitably defy the way the database is currently used. These arise from the increasing power of detection of DNA traces, the diversity of demands from police investigators and the growth of the bank itself. Examples of new requirements from the database now include familial searches, low-copy-number analyses and the correct interpretation of mixed samples. This paper aims to develop on the original way set in Québec to address some of these challenges. Nevertheless, analytic and technological advances will inevitably lead to the introduction of new technologies in forensic laboratories, such as single cell sequencing, phenotyping, and proteomics. Furthermore, it will not only request a new holistic/global approach of the forensic molecular biology sciences (through academia and a more investigative role in the laboratory), but also new legal developments. Far from being exhaustive, this paper highlights some of the current use of the database, its potential for the future, and opportunity to expand as a result of recent technological developments in molecular biology, including, but not limited to DNA identification.