NBOMe and NBOH are new psychoactive substances with potent activity on serotonin 5-HT2a receptors causing serious toxic effects, including serotonin toxidrome and death. The aim of this work was to develop a comprehensive MS/MS protocol, using triple quadrupole mass spectrometers coupled to LC and GC, for rapid screening and quantitation of NBOMes and NBOHs in seized blotter papers. Different scan methods (neutral loss, precursor ion or multiple reaction monitoring) were used to obtain structural information of phenylethylamine class. The developed protocol was validated for qualitative and quantitative analysis, showing a satisfactory limit of detection (1 ng/mL), with excellent selectivity, imprecision (intra and interday imprecision lower than 1.2 % RSD) and accuracy (between -7.1 and +5.6 %, n = 15), as well as bias values. The analysis of real samples shown that NBOH compounds were the most frequently detected, with concentrations ranging from 0.1 to 1,929 μg per blotter sample. Triple quadrupole mass spectrometers can be a useful tool for identification of new psychoactive substances. A comprehensive protocol using both LC-MS/MS and GC-MS/MS, with different scanning modes, have been developed and showed to be useful to screening NBOMe and NBOH in blotter papers.

This work examines organic impurity profiles of 3,4-methylenedioxymethamphetamine (MDMA) that has been synthesised from the "pre-precursors" catechol (1,2-dihydroxybenzene) and eugenol, via a safrole intermediate. MDMA was synthesised from the catechol- and eugenol-derived safrole intermediate via two routes, which resulted in the synthesis of MDMA from catechol via two routes (Route 1A and 1B) and from eugenol via two routes (Route 2A and 2B). Twelve organic impurities were identified in MDMA synthesised via Routes 1A and 1B, and eleven organic impurities were identified in MDMA synthesised via Routes 2A and 2B. Route specific organic impurities were identified in MDMA that indicated the "pre-precursors" catechol and eugenol were used in the respective synthetic routes. Route specific organic impurities were also identified in MDMA that indicated the route used to synthesise safrole from the "pre-precursor" and the route used to synthesise MDMA from safrole. Thus, the use of the "pre-precursors" catechol and eugenol and the synthetic route utilised could be ascertained by the organic impurity profiling of MDMA under the conditions used here.

Predicting the possible age-related changes to a child's face, age progression methods modify the shape, colour and texture of a facial image while retaining the identity of the individual. However, the techniques vary between different practitioners. This study combines different age progression techniques for juvenile subjects, various researches based on longitudinal radiographic data; physical anthropometric measurements of the head and face; and digital image measurements in pixels. Utilising 12 anthropometric measurements of the face, this study documents a new workflow for digital manual age progression. An inter-observer error study (n = 5) included the comparison of two age progressions of the same individual at different ages. The proposed age progression method recorded satisfactory levels of repeatability based on the 12 anthropometric measurements. Seven measurements achieved an error below 8.60%. Facial anthropometric measurements involving the nasion (n) and trichion (tr) showed the most inconsistency (14-34% difference between the practitioners). Overall, the horizontal measurements were more accurate than the vertical measurements. The age progression images were compared using a manual morphological method and machine-based face recognition. The confidence scores generated by the three different facial recognition APIs suggested the performance of any age progression not only varies between practitioners, but also between the Facial recognition systems. The suggested new workflow was able to guide the positioning of the facial features, but the process of age progression remains dependant on artistic interpretation.

Forensic serological analyses often rely on lateral flow immunochromatographic assays to detect proteins that are characteristic of forensically relevant body fluids. In this study, we demonstrate that a positive result, however, is not limited to target protein binding. Citric and lactic acids at various pH levels were tested using 9 different commercial immunochromatographic assays. Varying rates of false positive results were observed with commercial serological assays irrespective of brand or target biological fluid over a wide pH range. The use of kit specific buffers were only partially effective in mitigating the occurrence of organic acid-associated false positive results. Common household products containing organic acids were also tested and found to produce non-specific binding events. This is not to suggest that immunochromatographic assays are not useful as presumptive indicators of bodily fluids. Rather, this study provides a cautionary demonstration of the ease with which organic acids in common household products can generate false positives results. This finding underscores the presumptive nature of these antibody-based lateral flow assay systems.

In cases of incineration, where the identification of victims by conventional methods is impossible, teeth and dental materials become an available source of evidence - thanks to their ability to resist high temperatures. Currently, there is no experimental research to determine the behavior of the bracket and the dental structure when it is attached to the tooth after being exposed to high temperatures. An experimental in vitro study was carried out on 60 upper and lower premolar teeth (30 with a cemented bracket and 30 teeth without a bracket) that were exposed to six temperature ranges (200 °C, 400 °C, 600 °C, 800 °C, 1000 °C and 1200 °C). With the help of an Optiks® binocular stereomicroscope, macroscopic changes were described for each temperature; in addition, the mesio-distal diameter of the crown of the teeth and the bracket were measured before and after the incineration. A comparison of the diameters between the groups [the experimental group and the control group] and between the different temperatures was made. Both teeth, with brackets and without brackets showed macroscopic changes, such as fissures, cracks, fragmentation, enamel bursting and enamel and dentin separation according to the temperature range exposed. The detachment of the bracket was presented at 600 °C - leaving a mark on the dental surface. At above 1000 °C, the crown of the tooth with bracket acquired a pink color and the surface of the bracket became rough and opaque. At above 400 °C, both groups experienced an expansion in the crown dimension without significant differences. The results of this research suggest that teeth with attached brackets are equally resistant as the teeth without brackets, and that the adhesion of these attachments to the dental structure leave characteristics that allow them to be differentiated from teeth without braces -as well as suggesting the orientation to the temperature exposure.

The identification of confiscated commercial and military explosives is a crucial step not only in the uncovering of distribution pathways, but it also aids investigating officers in criminal casework. Even though commercial and military explosives mainly rely on a small number of high-energy compounds, a great variety of additives and synthesis by-products can be found that can differ depending on the brand, manufacturer and application. This makes the identification of commercial and military explosives based on their overall composition a promising approach that can be used to establish a pan-European Forensic Substance Database on Explosives. In this work, three analytical techniques were employed to analyze 36 samples of commercial and military explosives from Germany and Switzerland. An HPLC-HRMS method was developed, using 27 analytes of interest that encompass high-energy compounds, synthesis by-products and additives. HPLC-HRMS and XRD were used to gather and confirm molecular information on each sample and XRF analyses were carried out to gain insight on the elemental composition. Combining the results from all three techniques, 41 different additives could be identified as being diagnostic analytes and all samples showed a unique analytical fingerprint, which allows for a differentiation of the samples. Therefore, this work presents a set of methods that can be used as a foundation for the creation and population of a database on explosives that enables the assigning of specific formulations to certain brands, manufacturers and countries of origin.

While most evidence types considered by forensic scientists result from the interactions between criminals, objects or victims at crime scenes, dust evidence arises from the mere presence of individuals and objects at locations of interest. Dust is ubiquitous. Yet, the use of dust evidence is anecdotical and is limited to cases where rare and characteristic particles are observed. The dust at any given location contains a large number of particles from different types and the dust present on an object or individual traveling across locations may be indicative of the locations recently visited by an individual, and, in particular, of the presence of an individual at a particular site of interest, e.g., the scene of a crime. In this paper, we propose to represent dust mixtures as vectors of counts of the individual particles, which can be characterised by any appropriate analytical technique. This strategy enables us to describe a dust mixture as a mixture of multinomial distributions over a fixed number of dust particle types. Using a latent Dirichlet allocation model, we make inference on (a) the contributions of sites of interest to a dust mixture, and (b) the particle profiles associated with these sites.

This paper introduces a new, innovative approach to pre-crash velocity determination, namely the artificial neural networks. A perceptron based on a database obtained from NHTSA (National Highway Traffic Safety Administration) with numerous data concerning frontal vehicle crash tests: i.e. vehicle mass, deformation zone and deformation coefficients C1-C6. Part of the database entries were used to train the network to develop consistent accuracy and the remainder was used as validation and training sets.

Recent advances in microscopy have made it possible to collect 3D topographic data, enabling more precise virtual comparisons based on the collected 3D data as a supplement to traditional comparison microscopy and 2D photography. Automatic comparison algorithms have been introduced for various scenarios, such as matching cartridge cases [1,2] or matching bullet striae [3-5]. One key aspect of validating these automatic comparison algorithms is to evaluate the performance of the algorithm on external tests, that is, using data which were not used to train the algorithm. Here, we present a discussion of the performance of the matching algorithm [6] in three studies conducted using different Ruger weapons. We consider the performance of three scoring measures: random forest score, cross correlation, and consecutive matching striae (CMS) at the land-to-land level and, using Sequential Average Maxima scores, also at the bullet-to bullet level. Cross correlation and random forest scores both result in perfect discrimination of same-source and different-source bullets. At the land-to-land level, discrimination for both cross correlation and random forest scores (based on area under the curve, AUC) is excellent (≥0.90).

One of the primary interests of forensic sciences is the study of traces, better conceived as silent witnesses to criminal activity whose existence is attributable to Locard's principle. Thus, textile fibers are commonly exploited as they are easily transferred during contact which can vary in intensity depending upon the type of activity that occurred. Regardless, current knowledge pertaining to fiber transfer mechanisms, particularly in regards to blended textiles, is limited. It is recognized that the intensity of the contact, the type of textile as well as the size and type of fibers composing it have a significant influence on the amount of fibers transferred. However, when the donor textile is blended (eg. 50% cotton, 50% polyester), it often happens that one of the two types of fibers is transferred in greater proportion to the receiving surface (eg. 80% cotton and 20% polyester). The percentages indicated on the manufactured label are however not representative of the respective proportions (based on the number of fibers) of each type of fiber composing the fabric, but rather the weight of each respective type of fiber used to fabricate the garment. Therefore, the amount of collected fibers (traces) cannot be easily correlated to the proportions indicated on the manufactured label used to describe the textile. The objective of this study was to test the transfer capacities of blended textiles of different cotton and polyester proportions by performing several simulations under controlled conditions (i.e. contact between two textiles with a constant force and speed). The results were then correlated to the fiber type, morphology, and size. Overall, the project contributes to improving the comprehension of fiber transfer mechanisms, and provides insight on the quantity and the proportions of fibers capable of being transferred between the donor and the recipient textiles following a specific type of action and contact (legitimate or otherwise).