The potential of collaborative learning as a tool for forensic students: Application to signature examination.

Transferring theoretical knowledge to practical skills remains a big challenge in forensic science, especially in questioned documents. The examination of handwriting and signatures requires years of practice to develop the necessary skills. While students (and to some extent the general population) often have the impression that it is easy to differentiate handwriting from different persons, in practice, particularly when dealing with simulated signatures, there is a high risk of reaching a wrong conclusion when questioned document experts do not use a systematic approach and/or are not sufficiently experienced (see for example the famous French Dreyfus case). Thus, a novel teaching approach, based on collaborative learning, has been introduced in a theoretical handwriting class to improve the students' theoretical knowledge, and additionally make them aware of the limitations of their practical skills and give them tools to improve them in their future practice. Through five activities, the students took the roles of victims, forgers, teachers and experts and created their own learning materials (i.e. signatures and mock casework). During those interactive activities, they learned to describe their signature's characteristics, intra-variability and complexity, and thus evaluate their own signature's vulnerability (as potential victims). They learned techniques to simulate signatures and detect the resulting forgeries' characteristics (in the role of forgers). In the role of teachers, they prepared mock casework scenarios and gave feedback to their colleague's examination of the produced material. As experts, they carried out signature examination as they would in a proficiency test and were exposed to the difficulties an actual expert may encounter in practice. The evaluation of this novel teaching scenario was very positive, as students learned more extensively the possibilities and limitations of signature comparison. They were more active and motivated in their learning experiences. The teaching team also had an improved experience. Some students complained of an increased workload and imprecise instructions. Improvements were tested and are discussed in this paper.

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. Wastewater sampling was performed during its 2014 and 2015 editions. As the Swiss Festival's wastewater is conveyed to the sewage treatment plant (STP) of the nearby city, to assess illicit drug use when there is no festival (i.e. the background consumption) wastewater sampling was also carried out during an off-festival week in 2015. During the 2014 and 2015 editions of the Swiss Festival, WBE highlighted that the most consumed illicit drugs were cannabis, MDMA, cocaine and amphetamine. Excluding cannabis, the means per capita loads of all illicit drugs were not statistically different between both editions of the Swiss Festival. The results were then compared to those of an Australian festival which had also been subject of a quantitatively assessed illicit drug use study (Lai et al., 2013). This comparison confirmed that MDMA is highly prevalent, as well as amphetamine, although to a lesser extent. Consumption of cocaine (in Switzerland) and methamphetamine (in Australia) is also high, but their use seems to be related to their availability (i.e. to the country where the festival takes place). Furthermore, it was observed that MDMA and amphetamine are more consumed during the festival compared to normal times, when there is no festival. This might suggest that their availability is increased and therefore, that a market for these substances potentially exists during the festival. This last hypothesis was assessed by consulting drug seizures made by the police during the 2015 Swiss Festival. Despite very limited data, police records suggested that most of the drugs were purchased at the festival, which supports the previous hypothesis. Results validate, on the one hand, WBE as a useful indicator to monitor illicit drug use within festivals and on the other hand, the suggested framework for deploying WBE in such environment. In addition, this study suggests the need for prevention and harm reduction measures targeted on MDMA and amphetamine during the Swiss Festival, such as drug checking laboratories.

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. SETTING AND PARTICIPANTS: Catchment areas of 143 wastewater treatment plants in 120 cities in 37 countries. MEASUREMENTS: Parent substances (amphetamine, methamphetamine and MDMA) and the metabolites of cocaine (benzoylecgonine) and of Δ9 -tetrahydrocannabinol (11-nor-9-carboxy-Δ9 -tetrahydrocannabinol) were measured in wastewater using liquid chromatography-tandem mass spectrometry. Daily mass loads (mg/day) were normalized to catchment population (mg/1000 people/day) and converted to the number of combined doses consumed per day. Spatial differences were assessed world-wide, and temporal trends were discerned at European level by comparing 2011-13 drug loads versus 2014-17 loads. FINDINGS: Benzoylecgonine was the stimulant metabolite detected at higher loads in southern and western Europe, and amphetamine, MDMA and methamphetamine in East and North-Central Europe. In other continents, methamphetamine showed the highest levels in the United States and Australia and benzoylecgonine in South America. During the reporting period, benzoylecgonine loads increased in general across Europe, amphetamine and methamphetamine levels fluctuated and MDMA underwent an intermittent upsurge. CONCLUSIONS: The analysis of wastewater to quantify drug loads provides near real-time drug use estimates that globally correspond to prevalence and seizure data.

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. Among the targeted drugs, methamphetamine was consumed the most, followed by cocaine and 3,4-methylenedioxymethamphetamine (MDMA). Weekly patterns were observed where a peak during the weekend was present. The geographical analysis showed differences between the regions targeted. This observation may be related to socio-demographic aspects. The comparison of our study to other data sources from Australia showed a high consumption of methamphetamine in Sydney and Western Australia. The comparison between Sydney and different European cities revealed a difference in consumption, which is in line with traditional market indicators. The information obtained through wastewater analysis provides complementary information regarding illicit drug consumption, the size, and the evolution of the illicit drug market. This, ultimately, will assist authorities in making informed decisions.