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. © 2007 Forensic Science Society

Un programme d’enseignement et de recherche académique spécifique en science forensique au Canada : pourquoi ?

En 1963, le grand criminaliste américain Kirk soulevait la question suivante: «Where is criminalistics, forensic science, or whatever it may be called, going1» [Kirk, 1963, p. 138]. 46 ans plus tard, un rapport de l’Académie des sciences américaines vilipende cette discipline. Cet article propose un regard critique sur ce point de vue américain, tout en expliquant la nécessité d’une formation académique dédiée, comme celle lancée en 2012 au Québec

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. © 201

Expressing the value of forensic science in policing

© 2016 Australian Academy of Forensic Sciences. Only a small part of forensic science activities scattered across criminal justice systems is the object of scientific scrutiny, and is taken into account when evaluating the added-value brought by this discipline. Even in its more restricted definition, forensic science faces many embarrassing questions about its capacity to provide valid and reliably interpreted information in court. The inflation of control mechanisms increases costs and reduces the scope or availability of forensic information. The viability of forensic science, viewed through this lens, is questioned. To address this challenge, it is imperative to validly express forensic science contributions that are otherwise diluted across earlier processes. These include abductive and inductive species of inferences used in crime investigation, crime analysis and criminal intelligence. The ‘scientificity’ of these processes may be questioned, but it is not contested that they largely determine the global outcome of justice systems. As a result, they cannot be ignored. To unlock the debate, it is proposed to turn the forensic science focus from means (instruments, techniques, methods) to ends (what is the problem, what are the objectives?). This perspective naturally leads to proactive models of policing. It also provides possible frameworks to express various uses of the information conveyed by traces for solving problems. Reframed forensic science contributions are more validly expressed and the current debate can ultimately be transcended

Forensic-led regulation strategies: are they fit for security problem-solving purposes?

The dominant conception of forensic sciences is as a patchwork of disciplines assisting the criminal justice system, but the 2009 NAS report questioned the robustness of the scientific foundations of essentially all the forensic science disciplines. Yet, solutions intended to counter this disturbing assessment have mainly focused on methodology upgrades epitomized by quality management strategies that are crowned by accreditation of laboratories and certification of individual forensic scientists.While a forensic science world without quality management is senseless, its reported and observed implementation begs the question whether it has developed from a necessary tool to a constraint contributing to frame a mistaken view of experimental sciences dedicated to responding to criminal and litigation matters. This article questions the adequacy of forensic-led regulation strategies for security problem-solving, calling for a better understanding of its original link with criminological concerns. © 2018 selection and editorial matter, Quentin Rossy, David Décary-Hétu, Olivier Delémont and Massimiliano Mulone; individual chapters, the contributors

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

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

Making security glazing from modified TEMPO oxidized nanofibers and poly vinylbutyral

Safety glazing is a type of laminated glazing that holds together when shattered, due to the presence of an interlayer usually made of polyvinyl butyral (PVB). It is widely used in industrial application where the glazing could fall, or become a projectile to avoid serious injuries to humans after an impact with a foreign object. To replace the PVB, we have developed a modified cellulose nanofibers (NFC) by grafting poly(glycidyl methacrylate) with glycerol addition. This modification has improved the NFC pure performance as well as their compatibility with polar polymers. Therefore, this study reports the preparation and characterization of laminated glazing with composites of PVB reinforced with 40, 50 and 70% by weight of modified NFC. Composites interlayers are very transparent (up to 93% light transmission) with an interesting light character (up to 18.72% weight loss) in comparison to a PVB interlayer only. The chosen laminated glazing have been characterized by quasi-static (three-point bending) and dynamic impact loading (drop weight test). The quasi-static show the force–displacement curves of glazing while the dynamic testing give the energy absorption capability and maximum impact force. In our testing, the glazing with modified NFC have shown increased mechanical properties. Moreover, the laminated glazing made with an interlayer reinforced with 40% NFC exhibits the highest impact properties with a maximum force at break of 36,270 N and 24.81 J of absorbed energy. This study has shown that the modified NFC is indeed a lighter and environment-friendlier alternative for laminated glazing

Paper characteristics and their influence on the ability of single metal deposition to detect fingermarks

This study aims at exploring the way paper samples may impact the performance of Single-Metal Deposition (SMD II), a fingermark detection technique known for its versatility of application as well as its sensitivity regarding porous substrates. To get a broader view on how porous substrates may impact the SMD II performances, 74 North American and European papers types were collected, characterized (UV-visible and infrared spectroscopy, roughness, porosity, and surface pH), and processed as substrates bearing fingermarks. This part of the study represented a first valuable outcome by the number of samples considered. After processing with SMD II, the samples were characterized again with the techniques mentioned above, background staining and fingermark quality were assessed and associated with a quality score. Overall, no positive nor negative trend was observed between the paper characteristics and the SMD II performance. As a consequence, it is currently still not possible to predict if a paper sample will behave well or bad with SMD II. Of all the monitored parameters, the chemical composition of the surface coating (i.e., silica or calcium carbonate) may be worth exploring further, as it has been observed that some coatings undergo partial degradation during the SMD II process. As a result, secretion residue may be damaged by the chemical solubilization of the support layer if they failed to penetrate deeper into the substrate