Olivier Delémont

• Professor (full)
• University of Lausanne

Practice at our Center shows that approach using 3D surface imaging for morphometric comparison of patterned injuries does not always lead to accurate conclusions. We decided to evaluate whether a selection protocol focused on analysis phase could enable us to form an early assessment of the outcome of a comparison process, and then to select lesio...

3D-printed firearms, an emerging category of privately made firearms (PMF) produced beyond government control, have become increasingly prevalent due to technological advancements. They are now emerging as a cost-effective and reliable alternative to conventional firearms. Raised to public awareness following the 2013 release of the 3D-printed Libe...

The release of the plans of the 3D-printed Liberator firearm sparked a wave of new designs from creators worldwide, resulting in an extensive collection of 3D-printed firearm plans, in particular blueprints, and parts available for almost unrestricted download on the internet. Identifying and categorizing the diverse range of 3D-printed firearms an...

Deteriorated elements of ammunition can be found while investigating different types of events. Exposure to adverse environmental conditions may lead to metal alteration (corrosion) or organic material deposition (contaminations) on the exposed elements of ammunition. From a forensic perspective, both types of deterioration pose challenges when obs...

Since the blueprints of the Liberator were published and successfully tested, countless new designs for said 3D-printed firearms and 3D-printed firearm components have been created and made publicly available. These new 3D-printed firearms, which are praised by their designers as ever more reliable, can be found on the Internet with little effort....

Fire incidents are amongst the most destructive events an investigator might encounter, completely transforming a scene with most of the objects left in ashes or highly damaged. Until now, fire investigations relied heavily on burn patterns and electrical artifacts to find possible starting locations, as well as witness statements and more recently...

Following a chemical incident involving chemical warfare agents or more broadly, chemical weapons, there are two possible approaches in dealing with the traditional forensic analysis of contaminated exhibits. The first is to analyze the contaminated items under safe conditions (i.e. in laboratories dedicated to the handling of such substances), whi...

Forensic practice is the concluding practical course of the forensic science bachelor program at the School of Criminal Justice of the University of Lausanne. Learning activities are constructed around five main objectives for the resolution of simulated forensic case problems: 1) select relevant traces and items to be collected at the scene and pe...

Since its introduction in 1986, 3D printing technology is in constant development. 3D printers are becoming more and more performant and accessible. In 2013, the Liberator blueprints are released online. This single-shot pistol can be entirely manufactured using a 3D printer, except for the firing pin and the ammunition. First, this research aims a...

Daubert skews the contribution of forensic science because it only took into account its Galilean dimension (construction of general predictive models). However, forensic science should better be classified in the historical sciences (clinical approach to reconstruct a past event of presence or activity). We therefore need a complementary approach...

The use of ion mobility separations (IMS) in metabolomics approaches has started to be deeply explored in the last years. In this work, the use of liquid chromatography (LC) coupled to IMS‐quadrupole time‐of‐flight mass spectrometry (QTOF MS) has been evaluated in a metabolomics experiments using single injection of the samples. IMS has allowed obt...

While police chiefs are the main managers in policing, this chapter also underlines their role in the provision of forensic science, hardly known to be able to help define policing. A recent survey of high-ranking officers of various police forces in Quebec showed that police managers tend to focus mainly, if not exclusively, on the ability of fore...

Forensic technologies are now more easily transportable, fast and useable in the field by non-specialists. They help detect, collect and analyse a large volume of new and diverse traces generated by criminal activities. These changes, in order of magnitude, induce rapid digital transformations of forensic processes, requiring a radical shift in rol...

Arsonists may use ignitable liquids to start, accelerate and amplify fires. The sampling of volatiles present on the hands of suspected arsonists is therefore sometimes carried out in the course of the investigation of (possible) deliberate fires. Several collection protocols have been proposed, relying on the concentration of volatiles by the tran...

This article describes the application of a recently proposed framework for deploying wastewater-based epidemiology (WBE) to monitor illicit drug use within festivals (Benaglia et al., 2019). The festival under study was a week-long music festival in Switzerland (Swiss Festival) which attracted around 50,000 people daily. Wastewater sampling was pe...

DNA traces have made a significant contribution to criminal investigations for over 30 years, especially after the creation of DNA databases. Although the effectiveness of these databases is widely recognized, some issues – such as the retention period for DNA profiles – are still widely discussed because of the potential threat they pose to people...

The technique of fire investigation is a forensic domain in which expertise and analogies play a central role. To learn how fire investigators use these analogies to support their work, we conducted an ethnographic study in a Swiss forensic police department. To propose a suitable knowledge-management strategy, we also evaluated the knowledge conse...

3D surface scanning is a technique brought forward for wound documentation and analysis in order to identify injury-causing tools in legal medicine and forensic science. Although many case reports have been published, little is known about the methodology employed by the authors. The study reported here is exploratory in nature, and its main purpos...

Counterfeit luxury fashion goods have rarely been the subject of scientific studies. Very little is known about the mechanisms of this illicit market despite the apparent prevalence and their adverse consequences. Counterfeit watches remain one of the preferred targets in the luxury goods segment. The study of marks or traces in a forensic intellig...

For more than 10 years, forensic science has been at best, criticized for its lack of scientific foundations and at worst, presented as an oxymoron. An exclusive focus on standard operating procedures and quality management could cause forensic science to fall short of addressing the epistemological issue initiated by judges. This is particularly s...

A collaborative study conducted by three police forensic units, a DNA laboratory, and a forensic academic institute was undertaken in order to compare the performance of four different swabs in controlled and quasi-operational conditions. For this purpose, a reference swab (Prionics cardboard evidence collection kit) currently used within the polic...

Deliberate fires are a very common problem affecting all countries around the world. They create a high sense of insecurity within communities, consuming and straining many resources (human and financial). Yet, despite various attempts, significantly tackling and reducing deliberate fires has remained largely ineffective, mainly due to the case-by-...

Between 1920 and 1967, approximatively 8200 tons of ammunition waste were dumped into some Swiss lakes. This study is part of the extensive historical and technical investigations performed since 1995 by Swiss authorities to provide a risk assessment. It aims to assess whether explosive monitoring by passive sampling is feasible in lake-bottom wate...

The usefulness of forensic science continues to be questioned by evaluative studies taking as indicator its judicial contribution, mainly resulting in disastrous conclusions. The used indicators highly underrate and limit the actual contribution of forensic science, which are dependent on the definition, object, role, and integration in the crimina...

Counterfeit watches are products of illicit activity and contain traces of their production and distribution. Traces provide pertinent information through one of their fundamental characteristics: the ability to reveal links between specimens or cases. The aim of this study was to develop an analytical strategy to obtain the elemental composition o...

The practice of forensic science relies on the application of scientific principles and techniques for the questioning of 'traces', sometimes referred as 'physical evidence'. These traces represent the remnants of a past event or phenomenon, and the information they convey is generally gathered with the purpose to reconstruct and clarify what happe...

The Liberator is a firearm that can be manufactured from its blueprints by the means of a 3D-printer. This handgun is composed of nineteen pieces: eighteen made of printed polymer and one metallic nail. This study focuses on the physical traces which can be found and exploited from a forensic point of view after the discharging of such types of pis...

Wastewater analysis offers objective and complementary information to illicit drug agencies by monitoring patterns of illicit drug consumption. In this study, wastewater samples from three different wastewater treatment plants in Sydney, Australia were collected in March 2016. Ten targeted drugs were analysed and temporal and geographical analyses...

Tobacco smoking is the major cause of many chronic diseases, especially lung cancer. Knowledge about population-wide tobacco use and exposure is essential to characterise its burden on public health and evaluate policy efficacy. Obtaining such knowledge remains challenging with current methods (e.g., surveys, biomonitoring) but can be achievable wi...

At the individual level, exposure to contaminants is generally assessed by biomonitoring through the analysis of specific biomarkers in biological matrices. Yet, these studies are costly and logistically demanding, limiting their applicability to monitor population-wide exposure over time and space. By focusing on a selection of exposure biomarkers...

Between 1920 and 1967, approximately 8’200 tons of ammunition waste were dumped into several Swiss lakes. Previous studies based on grab sampling revealed traces of HMX, RDX and PETN in the water column of three studied lakes; however, these researches showed that the ammunition waste at the lake bottom was likely not involved in that contamination...

Despite a shared focus on crime and its ‘extended family’, forensic scientists and criminologists tend to work in isolation rather than sharing the data, methods and knowledge that will broaden the understanding of the criminal phenomenon and its related subjects. Bringing together perspectives from international experts, this book explores the in...

Study determining the factors regarding DNA trace processing in robbery cases.

Three-dimensional surface scanning (3DSS) and multi-detector computed tomography (MDCT) are two techniques that are used in legal medicine for digitalizing objects, a body or body parts such as bones. While these techniques are more and more commonly employed, surprisingly little information is known about the quality rendering of digitalized three...

The effectiveness of forensic science has been challenged by several studies, indicating that it is either scarcely used and thus not relevant or when it is used, its effects on case processing are minor. The majority of the studies focused on an understanding of forensic science as the application of scientific techniques to the matters of court....

Technology is increasingly offering new means of human behavior traceability. This situation is challenging the standing, scope and role of forensic science in the criminal Justice System. At the same time, criminology is developing methodologies that encompass virtual worlds, and deal with the increasing quantity of accessible digital data reflect...

Thanks to in-situ accumulation of pollutants in samplers and the ability to sequester pollutants from episodic pollution, passive sampling is a highly suitable tool to investigate current sources of hydrophobic organic compounds such as PCBs. In Switzerland, passive sampling was successively applied for the investigation of several rivers. In order...

This study firstly aims to assess the field performances of low density polyethylene (LDPE) and silicone rubber (SR) samplers for the monitoring of polychlorinated biphenyls (PCBs) in water regarding the uptake, the sampling rate (RS) estimated by using performance reference compounds (PRCs) and the time-weighted average (TWA) concentrations. The s...

Assessing illicit drug use through the analysis of wastewater is progressively being integrated into existing methods used to monitor the epidemiology of drug use. However, the approach's potential to deliver pertinent information for law enforcement has been discussed only limitedly. Thus, this work focuses on evaluating the added value of the app...

Cannabis consumption is a topical subject because of discussions about reviewing current regulations. In this context, having a more comprehensive approach to assess and monitor prevalence and consumption is highly relevant. The objective of this work was to refine current estimates about prevalence of cannabis use by combining self-report data and...

In order to broaden our knowledge and understanding of the decision steps in the criminal investigation process, we started by evaluating the decision to analyse a trace and the factors involved in this decision step. This decision step is embedded in the complete criminal investigation process, involving multiple decision and triaging steps. Consi...

Deliberate fires seem to be borderless and timeless events creating a serious security problem. There have been many attempts to develop approaches to tackle this problem, but unfortunately acting effectively against deliberate fires has proven a complex challenge. This article reviews the current situation relating to deliberate fires: what do we...

In past years, there has been a subsatantial improvement in the techniques used for the analysis of illicit drug and their metabolites in wastewater. The present article discusses the uses and limits of the technique for strategic and operative purposes in the field of criminal justice.

Bien que la science forensique et la criminologie partagent un objet commun, le crime comme réalité physique et sociale, elles tendent à se construire de manière indépendan- te et ont une propension à se profiler comme des disciplines bien établies et distinctes l’une de l’autre. A contre-courant, le présent article esquisse des pistes de réflexion...

Effectiveness measurement of forensic science has seen an increasing interest in the past decade. From an economical viewpoint, it has become more and more important to assess the contribution of forensic science in the criminal justice system. Hence, the number of studies allegedly investigating the effectiveness of forensic science on one or more...

With 6% of Europe’s freshwater resources, Switzerland is often considered the ‘water tower of Europe’. Over 8 millions residents rely on more than 57’600 farms to provide meat, milk, or eggs, with 1.58 million cattle, 1.58 million swine or 9.39 million poultry. Livestock farming produce the manure, which is a mixture of urine, faeces and infrastruc...

This study presents an innovative methodology for forensic science image analysis for event reconstruction. The methodology is based on experiences from real cases. It provides real added value to technical guidelines such as standard operating procedures (SOPs) and enriches the community of practices at stake in this field. This bottom-up solution...

The detection and identification of ignitable liquid residues in fire debris can be meaningful in fire investigations. However, background pyrolysis products and weathering hinder the identification and classification steps. In addition to those processes, the acidification of the ignitable liquids before the combustion process could make those tas...

In this work, mixtures of gasoline with sulphuric acid and diesel fuel with sulphuric acid were analysed by gas chromatography–mass spectrometry (GC–MS). The results showed considerable qualitative and semi-quantitative modifications in the chromatographic profiles of the ignitable liquids (ILs). In the case of acidified gasoline, the alteration of...

In an attempt to grasp the effectiveness of forensic science in the criminal justice process, a number of studies introduced some form of performance indicator. However, most of these indicators suffer from different weaknesses, from the definition of forensic science itself to problems of reliability and validity. We suggest the introduction of th...

The need to contextualise wastewater-based figures about illicit drug consumption by comparing them with other indicators has been stressed by numerous studies. The objective of the present study was to further investigate the possibility of combining wastewater data to conventional statistics to assess the reliability of the former method and obta...

The widespread use of digital imaging devices for surveillance (CCTV) and entertainment (e.g., mobile phones, compact cameras) has increased the number of images recorded and opportunities to consider the images as traces or documentation of criminal activity. The forensic science literature focuses almost exclusively on technical issues and eviden...

Although forensic science and criminology share a common object, that is crime as physical and social reality, they tend to be built up independently and evolve as distinct and well entrenched disciplines. Against this assumption, the present article sketches some reflexions about building a common knowledge, such as developed by a cohort of convin...

One aim of this study is to determine the impact of water velocity on the uptake of indicator polychlorinated biphenyls (iPCBs) by silicone rubber (SR) and low-density polyethylene (LDPE) passive samplers. A second aim is to assess the efficiency of performance reference compounds (PRCs) to correct for the impact of water velocity. SR and LDPE samp...

The forensic community tends furiously to be centred on new techniques and instrumentation development, while essentially obsessed by the production and quantification of evidence for the court. Enclosed in this trend, it loses sight of the work of the pioneers of the discipline who had a much wider perspective. They considered forensic science as...

Albeit it has rarely been scrutinised, the decision to use traces is crucial in forensic science. This decision is not as straightforward as it can appear, and it could benefit from a thorough examination. Regularly one has to assess how to handle large amounts of traces while confronted with limited resources. We suggest that the result of the dec...

This article presents a global vision of images in forensic science. The proliferation of perspectives on the use of images throughout criminal investigations and the increasing demand for research on this topic seem to demand a forensic science-based analysis. In this study, the definitions of and concepts related to material traces are revisited...

Fluctuations in ammonium ((NH4-N)) loads, measured using an ion-selective electrode installed at the inlet of a sewage treatment plant (STP), showed a distinctive pattern which was associated to weekly (i.e., commuters) and seasonal (i.e., holidays) fluctuations of the population. Diurnal profiles of benzoylecgonine (BE) and 11-nor-9-carboxy-delta-...

Durant les dernières années, la science forensique s’est amplement développée. Cependant, ses bases scientifiques et son efficacité dans le processus judiciaire ont récemment été remises en question. En conséquence, le nombre de publications étudiant l’efficacité ou l’efficience de la science forensique s’est multiplié en utilisant des indicateurs...

How the chemical analysis of counterfeit products can contribute to better understand the phenomenon of counterfeiting? To grasp this issue, an innovative approach based on a SPME GC-MS analysis of volatile compounds of thirty-nine perfumed counterfeit watchstraps has been implemented. The detection of dozens of compounds allowed the definition of...

Analytical results harmonisation is investigated in this study to provide an alternative to the restrictive approach of analytical methods harmonisation which is recommended nowadays for making possible the exchange of information and then for supporting the fight against illicit drugs trafficking. Indeed, the main goal of this study is to demonstr...

Analytical instruments based on InfraRed Absorption Spectroscopy (IRAS) and Gas Chromatography (GC) are today available only as bench-top instrumentation for forensic labs and bulk analysis. Within the 'DIRAC' project funded by the European Commission, we are developing an advanced portable sensor, that combines miniaturized GC as its key chemical...

A portable, advanced IR sensor in a hollow fiber matched to a silicon micromachined fast gas chromatography column can analyze illegal stimulants and precursors with nanogram-level sensitivity.

Little attention has been paid so far to the influence of the chemical nature of the substance when measuring δ (15)N by elemental analysis (EA)-isotope ratio mass spectrometry (IRMS). Although the bulk nitrogen isotope analysis of organic material is not to be questioned, literature from different disciplines using IRMS provides hints that the qua...

The flourishing number of publications on the use of isotope ratio mass spectrometry (IRMS) in forensic science denotes the enthusiasm and the attraction generated by this technology. IRMS has demonstrated its potential to distinguish chemically identical compounds coming from different sources. Despite the numerous applications of IRMS to a wide r...

Chemical compounds extracted from eggs and workers in F. selysi. Relative amount (%) of all the chemical compounds extracted from groups of workers or eggs originating from monogyne (Mo) and polygyne (Po) colonies. Retention time (RT) is the mean retention time of CC across all extractions. The 15 peaks with the largest variation of relative amount...

The ability of group members to discriminate against foreigners is a keystone in the evolution of sociality. In social insects, colony social structure (number of queens) is generally thought to influence abilities of resident workers to discriminate between nestmates and non-nestmates. However, whether social origin of introduced individuals has a...

«Money and illicit drugs trafficking, illicit drugs trafficking and money»: this is a well known association present in every mind. The production, transport and sale of illicit drugs constitute one of the major international illicit traffic that, through money laundering, funds many illegal activities. Regarding these activities there is a clear i...

The Radiello Passive Air Sampler is one of the latest innovations developed for the sampling of pollutants in the air by passive headspace. It has been reported that its properties allow an enhanced sensitivity, reproducibility and adsorption capacity. It therefore appears to be of interest in the extraction of potential residues of ignitable liqui...

A better integration of the information conveyed by traces within intelligence-led framework would allow forensic science to participate more intensively to security assessments through forensic intelligence (part I). In this view, the collection of data by examining crime scenes is an entire part of intelligence processes. This conception frames o...

Popularity of gamma-hydroxybutyric acid (GHB) is fairly stable among drug users, while the consumption of its chemical precursor, gamma-butyrolactone (GBL), is a growing phenomenon. Although conventional analytical methods allow to detect this substance in various matrices, linking a trace and a source is still a difficult challenge. However, as se...

Isotope ratio mass spectrometry (IRMS) has recently made its appearance in the forensic community. This high-precision technology has already been applied to a broad range of forensic fields such as illicit drugs, explosives and flammable liquids, where current, routinely used techniques have limited powers of discrimination. The conclusions drawn...

Forensic science is generally defined as the application of science to address questions related to the law. Too often, this view restricts the contribution of science to one single process which eventually aims at bringing individuals to court while minimising risk of miscarriage of justice. In order to go beyond this paradigm, we propose to refoc...

In arson cases, the collection and detection of traces of ignitable liquids on a suspect's hands can provide information to a forensic investigation. Police forces currently lack a simple, robust, efficient and reliable solution to perform this type of swabbing. In this article, we describe a study undertaken to develop a procedure for the collecti...

Isotope ratio mass spectrometry (IRMS) has recently made its appearance in the forensic community. This high-precision technology has already been applied to a broad range of forensic fields such as illicit drugs, explosives and flammable liquids, where current, routinely used techniques have limited powers of discrimination. The conclusions drawn...

A headspace solid-phase microextraction procedure (HS-SPME) was developed for the profiling of traces present in 3,4-methylenedioxymethylampethamine (MDMA). Traces were first extracted using HS-SPME and then analyzed by gas chromatography-mass spectroscopy (GC-MS). The HS-SPME conditions were optimized using varying conditions. Optimal results were...

Headspace solid-phase microextraction (HS-SPME) is assessed as an alternative to liquid-liquid extraction (LLE) currently used for 3,4-methylenedioxymethampethamine (MDMA) profiling. Both methods were compared evaluating their performance in discriminating and classifying samples. For this purpose 62 different seizures were analysed using both extr...

The evaluation of the self-heating propensity of a vegetable (or animal) oil may be of significant importance during the investigation of a fire. Unfortunately, iodine value and gas chromatographic-mass spectrometric analysis do not lead to meaningful results in this regard. To the contrary, differential scanning calorimetry (DSC), which does not m...

The identification of an arsonist remains one of the most difficult challenges a fire investigation has to face. Seeking and detection of traces of gasoline could provide a valuable information to link a suspect with an arson scene where gasoline was used to set-up the fire. In this perspective, a first study was undertaken to evaluate a simple, fa...