Mandats de recherche

Depuis 2015, la plupart des pays européens ont développé des instruments pour faire face au phénomène des violences politiquement et idéologiquement motivées, libellées alternativement terrorisme(s), radicalisation(s), ou extrémisme(s). Au vu de la vitesse avec laquelle les lois, politiques, programmes et mesures ont évolué au cours des dernières années en Belgique et en Suisse, il s’avère nécessaire de faire un point de situation et d’établir un état des lieux pour fournir une analyse compréhensive des dispositifs et pratiques antiterroristes.

Le projet poursuit deux objectifs. Le premier, celui de fournir une cartographie, pour chacun des pays, des acteurs, institutions et programmes qui constituent l’arsenal de ladite lutte contre les violences politico-idéologiques. Le deuxième, celui de décrypter à l’appui d’une étude de cas, l’opérationnalisation in concreto et au niveau micro du glissement vers la sphère préventive (pre-crime) et de ses implications politiques, sociales, juridiques et éthiques (post-terrorism). Il s’agira d’explorer in situ et à partir de la perspective des principaux préposés au déploiement des actions, les logiques préventionnistes à l’œuvre.

L’incertitude est une complication qui accompagne les scientifiques opérant dans le système de justice qui font de l’inférence et de la prise de décision un des aspects essentiels de leurs activités. L’inférence se rapporte à l’utilisation d’informations incomplètes (principalement données par des résultats scientifiques et des témoignages) afin de raisonner sur les hypothèses d’intérêt (par exemple, si une personne est ou non la source d’une trace retrouvée ou si elle a participé ou non à une activité criminelle). Les scientifiques sont également tenus à prendre des décisions pratiques (par exemple, concernant la séquence des tests de laboratoire à mettre en place). L’inférence et la décision nécessitent un soutien logique. Le raisonnement humain, si non assisté, entraîne une augmentation du biais par rapport à celui favorisé par le raisonnement probabiliste. Il s’agit là d’une source de préoccupation majeure, car les raisonnements fallacieux et les conclusions erronées d’experts peuvent conduire à des erreurs judiciaires.

Ce projet se focalise sur des études expérimentales dans certaines disciplines forensiques afin d’aider le scientifique (a) à la gestion de données complexes, (b) à la combinaison de masses d’information pour l’attribution d’une valeur probante conjointe, et (c) à la procédure d’identification d’une décision optimale. Ces défis seront abordés au moyen de la théorie des probabilités et de la théorie (Bayesienne) de la décision. Ces éléments seront combinés et exploités dans un environnement visuel. Les modèles issus de la construction de Réseaux Bayesiens (en anglais, Bayesian networks) - auront un impact sur de multiples domaines d’expertise dans lesquelles le type de données et la gestion de l’incertitude représentent également des contraintes spécifiques (par exemple, le domaine du dopage ou de l’estimation de l’âge d’une personne).

Since 2010, over 2000 people have been killed by firearms in Switzerland (compared to ca. 1500 persons per year in France). While the small arms survey estimates a relatively high firearms density in Switzerland (27.6% of the inhabitants possess at least one firearm) , their use for criminal purposes is relatively low compared to other countries such as the United States . More than 10 000 homicides are due to firearms each year in the USA (and 20 000 deaths are additionally caused by firearms due to suicides and accidents). Given their increased use in burglaries, organized crime and terrorism acts worldwide, it is a major forensic concern to be able to determine who pulled the trigger and/or who was present at the time of shooting. The analysis of gunshot residue (GSR) is routinely used in forensic laboratories to help answer such questions and reconstruct criminal events involving firearms. GSRs are particles produced when a firearm is discharged. They are expelled around the firearm and deposited on the hands and clothing of the shooter, and to some extent also on bystanders and targets. Their detection on these surfaces may, for example, indicate that a firearm was recently used. In practice, the investigation of inorganic GSR from the primer is well established in forensic science laboratories, using scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM-EDX). For this purpose, GSRs are generally sampled from a suspect’s hand using double-sided adhesive-coated aluminium stubs. However, many contamination sources of particles associated with inorganic GSR (such as lead, antimony and barium) have been reported. Moreover, the increasing use of heavy metal-free ammunition also significantly complicates interpretation of the source of such residues. Therefore, the study of organic GSR from the unburnt propellants is considered a necessary complement to IGSR analysis. Liquid chromatography methods coupled to mass spectrometry (LC-MS) were recently proposed for that purpose. Thanks to the improved sensitivity of contemporary instrumentation, as well as the applicability of the same sampling method to both organic and inorganic residues, the implementation of organic GSR analysis in forensic laboratories seems now a realistic endeavour. However, in order to provide a real added benefit to forensic investigations of firearm events, it should be applied in combination with the routine inorganic analyses with minimal loss of target material for both types of GSR constituents.Thus, this project aims at developing an operational methodology for the combined detection of inorganic and organic GSR. Several sampling options will be explored to maximise IGSR and OGSR recovery, followed by SEM-EDX and LC-MS analyses. For example, while two samples could be collected from a surface, this would risk halving the recovery rate for each type of GSR. The best option would thus be to collect only one sample, that would then be analysed sequentially for inorganic and organic target compounds, respectively. However, this approach requires thorough optimisation to minimise possible losses of trace evidence during the first analysis stage. Once the most efficient methodology has been determined, operational considerations will also be assessed, before implementation in forensic casework (in collaboration with the Swiss forensic police services). In parallel, a survey of the combined prevalence of the target compounds will help to evaluate the risk of contamination from environmental sources or secondary transfer. This will enable forensic science laboratories to exploit the full evidentiary value of GSR collected from suspects and victims of firearm incidents.

During latent print comparison, a non-mated print will be colloquially qualified as a “close nonmatch” (CNM) to the mark when it shows a level of agreement that could have misled an examiner to erroneously conclude that it was from the same source as the mark. These CNM prints are of crucial importance in developing the expertise of latent print examiners because they constitute the worst case scenario for a comparison between impressions originating from different sources. Because of the nature of the algorithms used in Automated Fingerprint Identification Systems (AFISs) (which are designed to find the closest matches contained in the database), combined with the ever-enlarging set of prints in their gallery, it is expected that examiners will increasingly face comparisons involving CNMs.

The issue facing the fingerprint community is that it does not have any repository of known cases including CNMs from which comparison exercises can be drawn. This is largely because CNMs are so time-consuming to locate. Over time, anecdotal cases have been shared in the community, but without any systematic organization to the data or means to search them available to law enforcement agencies. Additionally, these cases were submitted by examiners from casework, thus the ground truth state of the image pairs was unknown.

In this context, RTI International and University of Lausanne (Unil) present a proposal aimed at addressing CNM topics and delivering on the following objectives:

1. A ground truth library of marks and prints: Using an innovative partnership model to leverage an international network of public and private agencies and members of academia representing some of the top experts in the field, an international close nonmatch library (ICNML) of 1,000 cases will be prepared offering a repository of relevant and realistic marks and prints of known ground truth from 100 donors.

2. An evaluation of examiner understanding of CNMs: A list of red flags for CNMs will be developed based on expert input and discussion, and this list will be tested for its ability to predict the occurrence of CNMs. This information will increase our understanding of how well examiners understand CNMs and will allow for training recommendations to be made.

Developed using a crowd-sourcing approach to the research, the ICNML will be the first expert evaluated library of its type that will be made available to authorized agencies with a view toward promoting the training (and continuing education) of examiners, generating proficiency tests, providing images for use in research, and assisting in benchmarking AFIS systems.

« Témoignages d’enquêteurs » est soutenu par le Fonds d’innovation pédagogique de l’Université de Lausanne. Il propose la création d’un carnet de bord via une application mobile destinée à encourager la pratique réflexive sur le caractère éprouvant du processus de recherche et plus largement l’acquisition de compétences transversales notamment sur la gestion et l’analyse de ses propres émotions. Ce projet vise à favoriser la pratique réflexive individuelle sur les compétences mobilisées et les émotions ressenties lors d’une démarche de recherche qualitative appliquée. Il ambitionne ensuite, au travers de séances de jeux de rôle en ce qui concerne les compétences mobilisées et de focus groupe s’agissant des émotions ressenties, de poursuivre cette réflexion collectivement, puisqu’elle est réputée propice au développement de nouveaux apprentissages. En ce sens, « Témoignages d’enquêteurs » mobilise ainsi des techniques d’enseignements réputées mettre à profit et en valeur la diversité, la participation active et la coopération des étudiants en les impliquant dans des activités communes pour qu’ils bénéficient de l’ensemble des ressources du groupe.

La philanthropie, phénomène gagnant en légitimité politique et sociale, semble pourtant encore méconnue d’un point de vue des sciences sociales, particulièrement en Europe. Si nombre d’évaluations quantitatives sur les impacts des actions philanthropiques ont récemment vu le jour, leurs effets sur les normes sociales restent peu décrits. Cette recherche se propose, au travers du prisme de l’entrepreneuriat moral (Becker, 1973), d’analyser le phénomène philanthropique et son éventuel impact normatif sur une société civile donnée. Une méthodologie qualitative et quantitative est mobilisée dans l’optique d’explorer les rôles des acteurs de la philanthropie (philanthropes, récipiendaires, intermédiaires) ainsi que les potentiels mécanismes à l’œuvre dans la création de normes sociales, voire légales, dans la société dans laquelle eux-mêmes évoluent. Par ce biais, cette étude se propose de mettre en évidence les enjeux émergeant de l’existence d’une relation liant une autorité normative souvent dotée d’un pouvoir économique important (le philanthrope), à une autorité politique en prise avec des défis économiques, sociaux et environnementaux complexes.

Political grievance, resulting from the frustration of many young men with the conflicts in the Arab Mashreq and the suffering they cause among the civilian population, can lead to the experience of collective strain. While most individuals experiencing strain will adopt non-violent coping, a small minority will engage in acts of politically motivated violence (PMV). Research investigating the connection between collective strain and PMV from a bottom-up perspective is rare. The proposed study, using a qualitative approach and drawing on knowledge and expertise developed in criminology and political science, aims to gain insights into young men’s understandings of their engagement in PMV. Thereby, it has the potential to tap into hitherto unexplored aspects of the issue and inform fruitful, prevention-oriented policymaking.

Cette recherche collective pluridisciplinaire et internationale porte sur le désengagement des comportements délinquants en France et en Suisse. L'angle d'analyse se situe au croisement entre l'étude des dispositifs de prévention de la récidive mis en oeuvre par les institutions socio-judiciaires et l'analyse des parcours biographiques des personnes qui en ont été la cible.

As submitted by the proposer: The latent print comparison field has long been at the forefront of forensic science reform, conducting research to meet the challenges of critics, and producing error rate studies that establish the foundational validity of the comparison process. However, these studies have largely focused on fingerprints only, and palm impressions have been hitherto neglected. RTI International and the University of Lausanne have partnered to conduct a black box error rate study using exclusively palm print impressions. The researchers seek to begin establishment of the foundational validity of palmar friction ridge comparisons by empirically determining estimated error rates. The researchers will also investigate the relative strengths and weaknesses of both frequentist and Bayesian approaches to the presentation of error rate information in the courtroom, and provide recommendations that will assist examiners with their testimony about all friction ridge comparisons -- not only palms. This project will take place over two calendar years, and will involve partnerships with several forensic laboratories and the participation of approximately 150 working latent print examiners. More than 500 known ground truth palmar impressions of diverse size, quality, substrate, and development techniques will be collected from our partner laboratories to make up the test sample pool, and each latent print examiner study participant will complete 75 trials, resulting in an estimated 11,000+ presentations of palmar images. Trials will include both same-source and challenging different-source trials to allow both false-positive and false-negative estimates to be made. Error rates will be calculated for all trials in aggregate, but also stratified by size and quality, which will allow examiners to select the error rate that most closely corresponds to the size or quality of the impression(s) in the case when presenting testimony. Results will be disseminated to the forensic and legal communities via presentations at professional meetings, an article in a peer-reviewed scientific journal, and the presentation of a webinar. Additionally, the researchers will develop a web-based application specifically designed for computing confidence intervals and credible intervals. This application will demonstrate the benefits and limitations of both frequentist and Bayesian approaches in the context of error rates in friction ridge comparisons; and will be freely available for public use. Finally, a primer on error rates in friction ridge comparisons will be developed and distributed to the court system to educate jurors who will hear friction ridge testimony. 

Identification represents a very important domain in forensic science. This research program aims to investigate the use and the value of two scientific approaches, say questioned documents examination and the salivary microbiome as methods for human identification . The two main aspects of interest from an evaluative point of view will be (a) the intra- and (b) the inter-variability of the scientific evidence features. These terms refer to how much the findings (for example the saliva microbiome or a set of handwriting features) differ in a given individual and between different individuals, respectively. The measure of the intra- and inter-variability allows one to subsequently assess the potential use of a method for human identification, offering a probabilistic measure of the robustness of the link established between an individual and a given characteristic.That use of probabilistic reasoning in the legal process is not without controversy. The widespread application of scientific evidence in forensic science and notably on genetics and handwriting has brought to some prominence the issue of close relatives who share similar characteristics (for example, identical twin share the same DNA profile). In a particular investigation, it may be suggested that a close relative of the suspect was the person at the origin of the recovered (biological) sample or of the handwriting text. Practically, we will especially focus our research on human identification of very close relatives, such as twins.Forensic science and judicial literature has also pointed out the utility of methods that deal with formal analysis of rational thinking. Notably, it has been underlined that complex frameworks of circumstances - situations involving many variables (i.e. handwriting characteristics and microbiome profiles) - require a logical assistance. Methods of formal reasoning have been proposed to assist the forensic scientist to understand the dependencies that may exist among different aspects of the evidence (i.e. multiple items of evidence). Probabilistic graphical models, such as Bayesian Networks, provide a valuable aid for representing relationships among characteristics in situations of uncertainty. They assist the user not only in describing a complex problem and communicating information about its structure but also in calculating the effect of knowing the truth of one proposition or one piece of evidence on the plausibility of others. This inferential aspect will be addressed.The key result of this is the development of an original modelling environment to solve crucial societal problems of justice with innovative scientific solutions.

Ce projet décrit et analyse les logiques et les enjeux d'une stratégie de "co-production" de la sécurité à l'échelon local, à l'appui d'un devis de recherche mixte et en mobilisant des connaissances managériales, criminologiques et juridiques.

Latent prints that have insufficient characteristics for identification often have discernable characteristics that could form the basis for lesser degrees of correspondence or probability of occurrence within a population. Currently, those latent prints that experts judge to be insufficient for identification are not used as associative evidence. How often do such prints occur? What is their potential value for association? Would they actually impact case investigations or prosecutions in a useful way?
The answers are important. We could be routinely setting aside a very important source of associative evidence, with high potential impact, in many cases; or such prints may be of very low utility, adding very little, or only very rarely contributing to cases in a meaningful way. This project will address these questions, providing a factual basis to set the priority for development and validation of methods to exploit the use and associative value of these prints.
There are three, one-year Phases. In Phase I we will work with a range of state and local laboratories to measure how often, and at what levels of associative value, these prints occur in casework. A maximum potential associative value will be measured based on modeling withinvariability and between-variability of AFIS scores. This method incorporates (1) latest generation feature extraction, (2) a (minutiae-only) matcher, (3) validated distortion functions, and (4) NIST SD27 database calibration. Observed associative value distributions will be determined for violent crimes, property crimes, and for prints meeting exisiting objective measurements of latent print quality.
This will provide, for the first time, a measurement of the occurrence and associative value of NVID latents in casework. The actual usefulness of these prints depends on the case context. In Phase II we will work with investigators, prosecutors and crime laboratories to study prints found in well-defined case contexts. Phase II will answer whether, how often, and to what degree associations from these latent prints could answer questions of relevance within specific case contexts.
In Phase III we will (1) review our results with key constituencies (investigators, crime laboratories, attorneys and judges) to assess the practicality and effectiveness of this form of evidence, (2) incorporate selected measurement and/or process improvements, and (3) fill identified data gaps through additional collections and analyses.
Project results will provide a reasonable measure of the extent to which latent prints that are currently set aside as of no value for identification can serve as useful associative evidence.

Latent prints that have insufficient characteristics for identification often have discernable characteristics that could form the basis for lesser degrees of correspondence or probability of occurrence within a population. Currently, those latent prints that experts judge to be insufficient for identification are not used as associative evidence. How often do such prints occur? What is their potential value for association? Would they actually impact case investigations or prosecutions in a useful way?

The answers are important. We could be routinely setting aside a very important source of associative evidence, with high potential impact, in many cases; or such prints may be of very low utility, adding very little, or only very rarely contributing to cases in a meaningful way. This project will address these questions, providing a factual basis to set the priority for development and validation of methods to exploit the use and associative value of these prints.

There are three, one-year Phases. In Phase I we will work with a range of state and local laboratories to measure how often, and at what levels of associative value, these prints occur in casework. A maximum potential associative value will be measured based on modeling within variability and between-variability of AFIS scores. This method incorporates (1) latest generation feature extraction, (2) a (minutiae-only) matcher, (3) validated distortion functions, and (4) NIST SD27 database calibration. Observed associative value distributions will be determined for violent crimes, property crimes, and for prints meeting existing objective measurements of latent print quality.

This will provide, for the first time, a measurement of the occurrence and associative value of NVID latents in casework. The actual usefulness of these prints depends on the case context. In Phase II we will work with investigators, prosecutors and crime laboratories to study prints found in well-defined case contexts. Phase II will answer whether, how often, and to what degree associations from these latent prints could answer questions of relevance within specific case contexts.

In Phase III we will (1) review our results with key constituencies (investigators, crime laboratories, attorneys and judges) to assess the practicality and effectiveness of this form of evidence, (2) incorporate selected measurement and/or process improvements, and (3) fill identified data gaps through additional collections and analyses. Project results will provide a reasonable measure of the extent to which latent prints that are currently set aside as “of no value for identification” can serve as useful associative evidence.

Ce projet s'intègre dans le cadre du développement et du renforcement des capacités d'analyse du CICOP (Concept Intercantonal de Coordination Opérationnelle et Préventive). Il consiste en la mise en oeuvre opérationnelle et la validation de la méthodologie par l'ajout d'un composant technique capable d'automatiser la détection de changements dans les données de la criminalité en se basant notamment sur la classification situationnelle et les autres méthodes de détection déjà utilisées par le CICOP. 

At a time when there are over 9 million criminal proceedings in the EU every year, and the European Commission is promoting principles such as equality of arms to provide all parties with the protection of a fair trial, it is discomforting to learn that decades of behavioural studies have shown that practical human decision-making is not as good as we think it is. It is regularly liable to many forms of inconsistency. Also, with a public and media that tend to be more demanding and less forgiving, inference and decision-making in legal contexts with its potentially pervading consequences for defendants’ personal lives attract utmost attention. Much current research concentrates on a descriptive approach to this topic, in the sense of analysing instances of potential miscarriages of justice, but researchers largely avoid the normative questions of how thinking and decision-making ought to be assessed (e.g., logical coherence). Most likely, this is because normative insight often reveals where intuitive perceptions go astray, which is a result that people dislike. Our proposal for a way to deal with this risky topic is to act on the interdependency between forensic science and the law. By relying on the most recent concepts for graphical decision-analytic modelling, this project takes on the task of working out normative decision schemes through which forensic scientists and other participants in legal proceedings can beneficially interact when using scientific evidence as a core element in legal decision-making. The focus is on forensic interpretation, which is the use of forensic science to help reduce uncertainty about propositions of legal interest. The normative perspective makes this project both deep-probing and penetrating, as it will provide compelling analytical schemes with a computational basis to ensure clarity, balance and transparency along with argumentative rigor, and a host of fundamental insights into the workings of contemporary legal systems. 

The Swiss Federal Statistical Office (FSO) published for the first time detailed statistical data about homicides and suicides caused by firearms in 2009 . It showed that about 20% of the victims of homicides were killed by firearms in 2014, and that 28% of the suicides were committed with firearms (corresponding to about 250 deaths by firearms every year in Switzerland). Moreover, firearms were also used in numerous other infractions (for examples 299 hold-ups were counted in 2014). During the investigation of these serious incidents, police forces must often determine who pulled the trigger. In this light, the main tasks of forensic scientists are to help determine whether a particular firearm has been used and whether a person was recently in the proximity of a firearm discharge or had a contact with a source of gunshot residues (GSR). The question of firearm identification is the main subject of the scientific literature on firearms investigation, and is mainly solved by physical examination of firearms, bullets and cartridges. The second issue concerns the chemistry of firearms' ammunitions and can mainly be resolved by the examination of GSR produced during the discharge of a firearm. These residues are distributed around the discharging firearm and can be deposited on the hands and clothing of the shooter and to some extent on bystanders and targets. Their detection may for example give an indication that a firearm was recently used. In practice, the investigation of inorganic GSR from the primer is well established in forensic science laboratories. For that purpose, GSR are generally sampled from a suspect (hands, hair and face) and his belongings on double-sided adhesive coated aluminium stubs. However, many contamination sources for inorganic GSR particles (such as lead, antimony and barium) were reported and the increasing uses of lead free ammunition significantly complicate the interpretation on the origin of such residues. Therefore, the study of organic GSR from the unburnt propellants are considered today as a necessary element for the identification of shooters and bullet holes, and this is even more important if no primer residue can be detected. While this need was recognised some time ago and a certain amount of research was published since the 1980s, few recent studies exist on this subject and almost no forensic laboratory have routine procedures for parallel inorganic and organic GSR detection. Moreover, the difficulties of recovering small quantities of organic GSR on the hands and clothing of a person having used a firearm also represented a major practical limitation and interpretation of the results in a legal perspective was hardly addressed because of the lack of fundamental data on the transfer and persistence mechanisms of organic GSR. A forensic methodology to apprehend such issues will be formalized to answer recurrent questions occurring during investigative processes involving shooting. Determining essential factors changing with time and how they are affected given known conditions should allow establishing individual or combined kinetics. This should lead to a better fundamental understanding of detection issues with valid evidential answers in real casework. This project will allow forensic science laboratories in Switzerland and around the world, as well as Courts of law, to exploit the full evidentiary value of GSR collected from suspects.

 Dans le domaine de la science forensique, les étudiant·e·s doivent régulièrement appliquer en pratique les concepts théoriques appris en cours. La majorité des cours théoriques sont accompagnés de travaux pratiques que seule une partie des étudiant·e·s  suivent. Hors, les résultats pratiques en expertise d’écriture et signatures ont révélé une grande difficulté des étudiant·e·s  lors du transfert de la théorie à la pratique. Ce domaine dont la théorie est à premier abord très simple relève en effet toute sa complexité lors de la mise en œuvre pratique des concepts appris, qui est quant à elle très complexe et subtile.

Ce projet pédagogique vise donc à décloisonner l’apprentissage pratique et théorique en dédiant une partie importante du cours à la mise en pratique des concepts présentés de manière interactive. Il s’agit notamment d’impliquer activement les étudiant·e·s  dans leur apprentissage afin de les préparer à résoudre de manière autonome les situations qu’ils retrouveront plus tard dans leur vie professionnelle. Les étudiant·e·s  développeront par eux-mêmes au travers de l’expérimentation en groupes, des solutions à des problèmes réels, en s’inspirant notamment d’une technique d’apprentissage appelée collaborative learning. Dans le cadre du cours, les étudiant·e·s  seraient ainsi amenés à effectuer des jeux de rôle et des jeux de simulation, en prenant alternativement  la place de l’expert en écritures ou du faussaire dans le but de maîtriser à travers une recherche guidée des concepts de premier abord difficiles.

Ce projet a donc pour but d’encourager les étudiant·e·s à participer de manière active, collaborative et pratique à leur propre apprentissage pour atteindre de manière plus efficace les objectifs pédagogiques du cours expertise en écritures et signatures.

Ce projet explore les trajectoires des étudiants en criminologie de Lausanne, au regard notamment de leur cursus universitaire et professionnel. Il s'intéresse d'une part à leur parcours avant leur entrée dans le Master en criminologie et sécurité, pendant et dans les 3 ans qui suivent l'obtention de leur diplôme. Il explore d'autre part leurs représentations de la criminologie, de l'objet crime et des réactions sociales qui lui sont opposées, en lien avec leurs projections individuelles et professionnelles qu'ils nourrissent à ces différentes périodes. La subvention obtenue est utilisée pour construire les questionnaires d'entrée, de sortie et respectivement de suivi des candidats à l'obtention du Master en criminologie et sécurité

 Si l’on considère la récurrence des problématiques liées au temps en science forensique, une approche systématique ainsi qu’une meilleure compréhension fondamentale de ces notions sont nécessaires. C’est pourquoi un nouveau cours a été introduit récemment dans le cursus des étudiant-e-s de master en science forensique. Leur programme étant déjà suffisamment chargé, ce cours n’a pas pour but d’introduire de matière supplémentaire mais, en se basant sur les notions acquises précédemment, de permettre aux étudiant-e-s de considérer et intégrer les aspects temporels dans la résolution de cas pratiques. Le cours intègre donc une partie interactive importante afin de faciliter l’apprentissage des étudiant-e-s et de leur permettre de développer leurs compétences de réflexion dans les situations réelles qu’elles et ils retrouveront plus tard dans leur vie professionnelle. L’introduction de l’apprentissage par résolution de problèmes soulève plusieurs questions pédagogiques, notamment le fait de disposer d’un nombre de problèmes suffisants et de les adapter aux objectifs d’apprentissage. Il faut également considérer l’encadrement des groupes d’étudiant-e-s et la formation spécifique des personnes qui les encadrent. Ainsi cette nouvelle approche devrait permettre d’atteindre les objectifs suivants:

• Soumettre aux étudiant-e-s du matériel stimulant la discussion de problèmes importants dans le domaine
• Proposer des problèmes provenant de situations forensiques réelles
• Guider les étudiant-e-s dans une réflexion critique en leur fournissant peu de ressource afin de les amener à la résolution de problèmes par eux-mêmes
• Amener les étudiant-e-s à travailler en collaboration dans des petits groupes de 3-4 personnes
• Stimuler les étudiant-e-s à identifier leur besoin en apprentissage et ressource
• Amener les étudiant-e-s à utiliser les connaissances acquises dans la résolution de nouveaux problèmes et identifier de nouveaux problèmes
• Apprendre une nouvelle approche pédagogique à l’enseignant-e.

Ce projet a donc pour but d’introduire deux nouveautés dans un cours théorique forensique: un concept, la notion de temps, et une méthode d’enseignement, l’apprentissage par problèmes. Ceci devrait permettre aux étudiant-e-s d’atteindre les objectifs d’apprentissage de manière plus efficace tout en participant au processus d’enseignement de manière active.

Situating events in time is an essential question in forensic sciences along with transfer and identification issues. In fact, if a person declares that he actually was on the crime scene at another time than the criminal event, the traces left (transfer) by this person (identification) would then lose all relevance. Up to date, among the typical questions raised during investigations (who, how and when), the time has generally been left aside. The reason for this can be traced to the complexity of the overall problematic, addressed by several scientists in very limited projects usually prompted by a specific case. Considering that such issues are recurrent in forensic sciences and transcend the treatment of each trace separately, a fundamental and systematic approach yielding to a framework that can be applied transversally to all physical evidence is undeniably needed.Aging of traces can follow many different pathways at considerably different rates. If reaction kinetics are reproducible under controlled circumstances, it is possible to estimate the time since transfer of a trace (for example the time of contact between a person’s finger and a surface or the time of shooting of a gun). This is a rather difficult challenge in most cases, because aging processes are influenced by many factors apart from time (initial composition, substrates, and storage conditions of traces); some of them considerably accelerating or quenching the aging. This research project will focus on two promising orientations in order to extract common mechanisms: aging of fingerprints and aging of gunshots residues. These were chosen because they represent two important problems encountered routinely in forensic investigation. The study of these processes will be carried out using strict aging protocols and integrating the specific constraints pertaining to the criminal justice system on the two types of traces complementary in their applications: fingerprints (traces originating from a person) and gunshot residues (traces originating from an object). A methodology to apprehend such problems will be formalized to answer recurrent questions occurring during investigative processes involving fingerprints, shooting and other forensic traces. The outcomes of the highlighted project orientations will be included in the definition of a common approach that may later be transposed to all types of evidence. Determining essential factors changing with time and how they are affected given known conditions should allow establishing individual or combined kinetics. Aging curves with known limit uncertainties can then be used to study trace evidence with respect of source inferences (likelihood ratio interpretation framework). This should lead to a better fundamental understanding of age determination issues with valid evidential answers in real casework.