Effects of chemical & biological warfare agent decontaminants on trace survival: Impact on DNA profiling from blood and saliva.

Forensic investigations following incidents involving chemical or biological agents present considerable challenges. Understanding the possibilities and limitations can aid in determining the most suitable procedures and enhancing the recovery of useful traces in these complex situations. This work complements previously published results on the effects of decontaminants on fingermarks deposited on glass.

Forensic exploitation of patterned injuries: Promoting structured analysis as an early assessment for comparison process.

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 lesions likely to lead to a probative conclusion. 23 blunt objects were used to create 65 patterned injuries on an experimental model simulating human skin.

The emergence of 3D-printed firearms: An analysis of media and law enforcement reports.

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 Liberator, these firearms are now more commonly encountered by police forces.

Investigating the availability of 3D-printed firearm designs on the clear web.

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 and components pose a challenge due to the abundance of designs available. Between 2021 and April 2023, data was collected on over 2,100 3D-printed firearm plans.

Cleaning deteriorated elements of ammunition: Development of a procedure applied to cartridge cases from the Second World War.

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 observing marks left by the firearms used to discharge the corresponding ammunition (e.

Was a 3D-printed firearm discharged? Study of traces produced by the use of six fully 3D-printed firearms.

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. Press reports have shown that various models of 3D-printed firearms have already been confiscated by law enforcement services around the world.

Ok Google, Start a Fire. IoT devices as witnesses and actors in fire investigations.

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 witness imagery. As Internet of Things (IoT) devices, often seen as connected smart devices, become more common, the various sensors embedded within them provide a novel source of traces about the environment and events within.

The potential of digital technologies in problem-based forensic learning activities.

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 perceive their potential value in the reconstruction process, 2) apply appropriate detection techniques in sequence to obtain clues of good quality, 3) process traces using Analysis, Comparison, Evaluation and Verification (ACE-V) methodology, 4) produce and summarise information in oral and written forms to help an investigation, and 5) work collaboratively to benefit from the diversity of group members. Simulating and supervising realistic activities is a complex task that became more and more challenging with a continuously increasing number of students over the years (from ca.

Effects of chemical warfare agent decontaminants on trace survival: Impact on fingermarks deposited on glass.

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.

Influence of the printing process on the traces produced by the discharge of 3D-printed Liberators.

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.

Use of ion mobility-high resolution mass spectrometry in metabolomics studies to provide near MS/MS quality data in a single injection.

The use of ion mobility separations (IMSs) 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 obtaining cleaner fragmentation spectra, of nearly tandem MS quality, in data-independent acquisition mode.

Detection of gasoline on suspects' hands: Study of different sampling alternatives.

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 transfer on PVC gloves and further passive headspace extraction with Activated Charcoal Strips (ACS).

How to share and utilise expertise in a police forensic department through externalisation and mutualisation.

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 conservation and sharing within the department.

Testing wastewater from a music festival in Switzerland to assess illicit drug use.

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.

Spatio-temporal assessment of illicit drug use at large scale: evidence from 7 years of international wastewater monitoring.

Background And Aims: Wastewater-based epidemiology is an additional indicator of drug use that is gaining reliability to complement the current established panel of indicators. The aims of this study were to: (i) assess spatial and temporal trends of population-normalized mass loads of benzoylecgonine, amphetamine, methamphetamine and 3,4-methylenedioxymethamphetamine (MDMA) in raw wastewater over 7 years (2011-17); (ii) address overall drug use by estimating the average number of combined doses consumed per day in each city; and (iii) compare these with existing prevalence and seizure data.

Design: Analysis of daily raw wastewater composite samples collected over 1 week per year from 2011 to 2017.

Touch DNA collection - Performance of four different swabs.

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 police forensic units and 3 challenger swabs (COPAN 4N6FLOQSwabs™ (Genetics variety), Puritan FAB-MINI-AP and Sarstedt Forensic Swab) were used for collecting DNA traces from previously used items (referred as "touch DNA" in this article) including on 60 collars, 60 screwdrivers and 60 steering wheels obtained from volunteers. For each comparison, the surface considered was divided into two equal components; one was sampled with the reference swab and the other with one of the three challenger swabs.

The use of wastewater analysis in forensic intelligence: drug consumption comparison between Sydney and different European cities.

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 were performed to obtain a better understanding of the type and amount of illicit drugs consumed in Sydney in comparison with similar studies conducted around Australia and in Europe.

Forensic intelligence on illicit markets: The example of watch counterfeiting.

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.

Monitoring of explosive residues in lake-bottom water using Polar Organic Chemical Integrative Sampler (POCIS) and chemcatcher: determination of transfer kinetics through Polyethersulfone (PES) membrane is crucial.

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 waters.

Deliberate fires: From data to intelligence.

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-case approach implemented in responding to these incidents.

Elemental analysis for profiling counterfeit watches.

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 of watchcases, by analysing a selection of 35 counterfeit watches.

How to recognise the traces left on a crime scene by a 3D-printed Liberator? Part 2. Elements of ammunition, marks on the weapons and polymer fragments.

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 pistols.

An exploratory study toward the contribution of 3D surface scanning for association of an injury with its causing instrument.

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 purpose was to get a first evaluation of the ability of an operator, by means of 3D surface scanning and following a simple methodology, to correctly exclude or associate an incriminated tool as the source of a mock wound.

Levels of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) in raw wastewater as an innovative perspective for investigating population-wide exposure to third-hand smoke.

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.

Mining the Chemical Information on Urban Wastewater: Monitoring Human Exposure to Phosphorus Flame Retardants and Plasticizers.

At the individual level, exposure to contaminants is generally assessed through the analysis of specific biomarkers in biological matrices. However, 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 to phosphorus flame retardants and plasticizers (PFRs), this study aims to explore the possibility of using wastewater as a complementary source of information about exposure.