Showing papers by "German Criminal Police Office published in 2021"

Morphing Attack Detection-Database, Evaluation Platform, and Benchmarking

Abstract: Morphing attacks have posed a severe threat to Face Recognition System (FRS). Despite the number of advancements reported in recent works, we note serious open issues such as independent benchmarking, generalizability challenges and considerations to age, gender, ethnicity that are inadequately addressed. Morphing Attack Detection (MAD) algorithms often are prone to generalization challenges as they are database dependent. The existing databases, mostly of semi-public nature, lack in diversity in terms of ethnicity, various morphing process and post-processing pipelines. Further, they do not reflect a realistic operational scenario for Automated Border Control (ABC) and do not provide a basis to test MAD on unseen data, in order to benchmark the robustness of algorithms. In this work, we present a new sequestered dataset for facilitating the advancements of MAD where the algorithms can be tested on unseen data in an effort to better generalize. The newly constructed dataset consists of facial images from 150 subjects from various ethnicities, age-groups and both genders. In order to challenge the existing MAD algorithms, the morphed images are with careful subject pre-selection created from the contributing images, and further post-processed to remove morphing artifacts. The images are also printed and scanned to remove all digital cues and to simulate a realistic challenge for MAD algorithms. Further, we present a new online evaluation platform to test algorithms on sequestered data. With the platform we can benchmark the morph detection performance and study the generalization ability. This work also presents a detailed analysis on various subsets of sequestered data and outlines open challenges for future directions in MAD research.

Cumyl-CBMICA: A new synthetic cannabinoid receptor agonist containing a cyclobutyl methyl side chain.

Abstract: Since the beginning of the phenomenon of new psychoactive substances (NPS), synthetic cannabinoid receptor agonists (SCRAs) have been the largest and most prevalent subclass of these drugs in Europe. Many countries implemented specific legislation scheduling classes of substances defined on the basis of their chemical structure to reduce supply. We describe the identification and analytical characterization within the EU project ADEBAR plus of 1-(cyclobutylmethyl)-N-(2-phenylpropan-2-yl)-1H-indole-3-carboxamide which resulted in the formal notification through the Early Warning System of the European Monitoring Centre for Drug and Drug Addiction (EMCDDA). This is the first identification of this new SCRA worldwide and the analytical data was distributed (inter-)nationally right after identification in 2019. First, the substance was isolated from the herbal material using preparative high-performance liquid chromatography (HPLC). Structure elucidation and analytical characterization were performed using gas chromatography-mass spectrometry (GC-MS), gas chromatography-solid state infrared spectroscopy (GC-sIR), liquid chromatography-electrospray ionization-quadrupole time of flight-mass spectrometry (LC-ESI-qToF-MS), Raman spectroscopy, and nuclear magnetic resonance (NMR) spectroscopy. The new compound contains a cyclobutyl methyl group as a side chain and has not been described in any patent to our knowledge. Based on the semisystematic nomenclature of SCRAs, we propose Cumyl-CBMICA as a short name for the compound.

Interpretation of chemical data from glass analysis for forensic purposes

Abstract: The aims of evaluating forensic evidence are to provide a transparent, coherent, and unbiased opinion of the value of the evidence to fact‐finders. Measurements from glass evidence in a hit‐and‐run, for example, can help decide if a particular vehicle was involved in the accident. The evaluation involves the comparison of the physical, optical, and chemical properties of the glass recovered from the broken window with glass fragments suspected of originating from the window. A standard method (ASTM E2927‐16e1) describes a consensus‐based approach to sampling, sample preparation, quantitative analysis and “match” criterion for comparison of chemical properties. The result is a binary decision of either finding a difference in the elemental composition (exclusion) or a failure to exclude, based on elemental composition. This study demonstrates the utility of likelihood ratio (LR) calculations using novel datasets of glass samples of known manufacturing history. The LRs calculated from comparing glass manufactured at three different plants over relatively short periods (over 2‐6 weeks) range from very low values (LR ~ 10−3) when the glass are manufactured at different plants or manufactured weeks‐months apart in the same plant to very high values (LR ~ 103) when the glass samples are manufactured on the same day. Although the glass samples being compared may not originate from the same broken window source, they do exhibit chemical similarity within these lower and upper bounds and the LRs presented here, for the first time, closely correlate chemical relatedness to manufacturing history, specifically the time interval between production. The work presented here supports the use of the match criteria recommended within ASTM E2927‐16e1 and provides a data‐driven path forward to expand on the interpretation of glass using LRs.

Insight Beyond Numbers: The Impact of Qualitative Factors on Visual Data Analysis

Abstract: As of today, data analysis focuses primarily on the findings to be made inside the data and concentrates less on how those findings relate to the domain of investigation. Contemporary visualization as a field of research shows a strong tendency to adopt this data-centrism. Despite their decisive influence on the analysis result, qualitative aspects of the analysis process such as the structure, soundness, and complexity of the applied reasoning strategy are rarely discussed explicitly. We argue that if the purpose of visualization is the provision of domain insight rather than the depiction of data analysis results, a holistic perspective requires a qualitative component to to be added to the discussion of quantitative and human factors. To support this point, we demonstrate how considerations of qualitative factors in visual analysis can be applied to obtain explanations and possible solutions for a number of practical limitations inherent to the data-centric perspective on analysis. Based on this discussion of what we call qualitative visual analysis, we develop an inside-outside principle of nested levels of context that can serve as a conceptual basis for the development of visualization systems that optimally support the emergence of insight during analysis.

New synthetic cannabinoids carrying a cyclobutyl methyl side chain: Human Phase I metabolism and data on human cannabinoid receptor 1 binding and activation of Cumyl-CBMICA and Cumyl-CBMINACA.

Abstract: Synthetic cannabinoids (SCs) represent a large group of new psychoactive substances (NPS), sustaining a high prevalence on the drug market since their first detection in 2008. Cumyl-CBMICA and Cumyl-CBMINACA, the first representatives of a new subclass of SCs characterized by a cyclobutyl methyl (CBM) moiety, were identified in July 2019 and February 2020. This work aimed at evaluating basic pharmacological characteristics and human Phase I metabolism of these compounds. Human Phase I metabolites were tentatively identified by liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-QToF-MS) of urine samples and confirmed by a pooled human liver microsome (pHLM) assay. The basic pharmacological evaluation was performed by applying a competitive ligand binding assay and a functional activation assay (GTPγS) using cell membranes carrying the human cannabinoid receptor 1 (hCB1 ). Investigation of the human Phase I metabolism resulted in the identification of specific urinary markers built by monohydroxylation or dihydroxylation. Although Cumyl-CBMICA was primarily hydroxylated at the indole ring, hydroxylation of Cumyl-CBMINACA mainly occurred at the CBM moiety. Both substances acted as agonists at the hCB1 receptor, although substantial differences could be observed. Cumyl-CBMINACA showed higher binding affinity (Ki = 1.32 vs. 29.3 nM), potency (EC50 = 55.4 vs. 497 nM), and efficacy (Emax = 207% vs. 168%) than its indole counterpart Cumyl-CBMICA. This study confirms that substitution of an indole by an indazole core tends to increase in vitro potency, which is potentially reflected by higher in vivo potency. The emergence and disappearance of SCs distributed via online shops carrying a CBM moiety once more demonstrate the "cat-and-mouse" game between manufacturers and legislation.

Glossary of methods and terms used in analytical spectroscopy (IUPAC Recommendations 2019)

Abstract: Recommendations are given concerning the terminology of concepts and methods used in spectroscopy in analytical chemistry, covering nuclear magnetic resonance spectroscopy, atomic spectroscopy, and vibrational spectroscopy.

Development and validation of an mRNA-based multiplex body fluid identification workflow and a rectal mucosa marker pilot study

Abstract: Molecular identification of body fluids and tissues is crucial in order to understand the circumstances of crimes. For that reason, molecular investigations used to identify body fluids/tissues have increasingly been examined recently. Various studies have proved that messenger RNA (mRNA) profiling is a sensitive and robust method for body fluid/tissue identification. The forensically relevant body fluids/tissues blood, semen, saliva, vaginal secretion, menstrual blood and skin have all been detected successfully by applying suitable mRNA assay. However, rectal mucosa, which can be found as evidence in sexual assault cases, has been neglected in forensic investigations. So far there is no mRNA marker to detect rectal mucosa, although anal penetration occurs in a large number of sexual assaults (23.2% of female victims and 50% of male victims). In this study, specific and sensitive mRNA markers for forensically relevant body fluids were adapted and validated in an mRNA multiplex assay for routine casework. This included the implementation of a DNA/RNA re-extraction method for automated extraction that can be integrated into casework without loss of DNA. This re-extraction method and the mRNA multiplex assay were tested using casework samples. PCR-primers were designed for the identification of rectal mucosa and the more effective marker MUC12 was integrated into an extended multiplex assay. The result of our study is a highly specific and sensitive mRNA multiplex assay plus an automated DNA/RNA re-extraction method, that can be integrated into casework and identify rectal mucosa for the first time.

Text-Linguistic Analysis in Forensic Authorship Attribution

Abstract: Authorship analysis of anonymous texts is one of the more frequently required tasks in a forensic setting. Its main purpose is either to gain information on the author’s linguistic and social background to support an investigation or to match an anonymous text to a suspect’s previous writings. One approach to authorship attribution is pragmatic stylistic analysis, which is grounded in text-linguistic research, cf. Brinker (2002), Sandig (2006), Puschel (2009), and Brinker et al. (2018), and holds a broad and holistic view on style. In its analyses, it focuses on the functional and pragmatic aspects of style as part of a communicative strategy. A central element, especially in Brinker’s approach, is the thematic text pattern. How individuals argue, how they arrange textual patterns and how they express their demands most certainly reveal aspects of their individuality (Brinker, 2002; Brinker et al., 2018), suggesting that these cannot be easily suppressed or disguised. The paper applies Brinker’s approach to three very short anonymous extortion letters illustrating how text-linguistic analysis can contribute to authorship attribution. Firstly, the text structure of the letters will be analyzed and secondly, the relations between text pattern and stylistic features will be examined in detail, and the relevance of the text patterns will be discussed with reference to the author’s idiolect. The paper aims to point out the possibilities of a more in-depth textual analysis beyond the analysis of surface structures, especially in cases of very small data sets. Cite as: Fobbe , JLL 9 (2020), 93–114, DOI: 10.14762/jll.2020.093

Forensische DNA-Methylierungsanalyse

Abstract: Die quantitative Analyse der relativen DNA-Methylierung gilt als eine der vielversprechendsten Methoden der molekularen Altersschatzung. Viele Studien der letzten Jahre identifizierten geeignete Positionen im Genom, deren DNA-Methylierung sich altersabhangig verandert. Fur den Einsatz dieser Methode in der Routine- bzw. Fallarbeit ist es von groser Bedeutung, angewandte Analysetechniken zu validieren. Als ein Teilaspekt dieser Validierung sollte die Vergleichbarkeit der Analyseergebnisse zur DNA-Methylierung mithilfe der Mini- und Pyrosequenzierung zwischen verschiedenen Laboren evaluiert werden. Die Arbeitsgruppe „Molekulare Altersschatzung“ der Deutschen Gesellschaft fur Rechtsmedizin (DGRM) fuhrte hierzu den ersten, technischen Ringversuch durch, der 4 Positionen in den Genen PDE4C, EDARADD, SST und KLF14 umfasste. Diese Marker waren in vorangegangenen Studien als altersabhangige Biomarker charakterisiert worden. Am Ringversuch nahmen 12 Labore teil, wobei jedes die Wahl zwischen der Minisequenzierung und/oder der Pyrosequenzierung fur die quantitative Methylierungsanalyse hatte. Jedem teilnehmenden Labor wurden Blut- und Speichelproben von 3 Personen unterschiedlichen Alters ubersandt. Die Wahl der Reagenzien fur die Probenbearbeitung wurde den Teilnehmern freigestellt. Die Ergebnisse der Minisequenzierung zeigten systematische Abweichungen zwischen den Laboren, die am ehesten auf die Verwendung unterschiedlicher Reagenzien und Analyseplattformen zuruckzufuhren sein konnen. Die Resultate der Pyrosequenzierung hingegen wiesen nicht auf systematische Abweichungen zwischen den Laboren hin, hier zeigte sich jedoch die Tendenz einer markerabhangigen Abweichung. Daruber hinaus konnten Unterschiede hinsichtlich technischer Probleme zwischen Laboren mit mehr Erfahrung in der jeweiligen Sequenzierungsmethode und Laboren mit weniger Erfahrung festgestellt werden. Sowohl die Beobachtung von systematischen als auch die von markerabhangigen Abweichungen lasst den Schluss zu, dass eine Ubertragung von Analysemethoden zwischen Laboren grundsatzlich moglich ist, eine Anpassung des jeweiligen Modells zur Altersschatzung jedoch notwendig sein kann.

Latent Fingermark Aging: Chemical Degradation Over Time

Abstract: This chapter presents an overview of the current knowledge regarding the chemical composition of fingermarks and its modification as a function of time, focusing primarily on the compounds targeted in fingermark detection and/or age estimation purposes. As numerous studies have been published regarding these constituents in various contexts, this discussion will pertain mainly to fingermarks and human skin secretions, with some in vitro experiments where relevant additional information is provided.

Recommendations for capturing signatures digitally to optimize their suitability for forensic handwriting examination.

Abstract: The use of digitally captured signatures in everyday course of business increases annually and, compared to pen and paper signatures, provides various advantages concerning the administration of documents. These signatures may also become subjects of a forensic handwriting examination and, therefore, in order to optimize their suitability for this purpose, they should satisfy several requirements. This paper presents recommendations drawn up by forensic handwriting examiners associated with ENFHEX (ENFSI) in a project aimed at defining best practices in forensic examination of digitally captured signatures. The paper is dedicated mainly to hardware and software developers, providers, and user institutions of digitally captured signature technologies to improve their practice to a level optimized for forensic handwriting examination. The most important requirements outlined in this paper concern digitally captured signature data, hardware, and software used to acquire these data, as well as optimized signing conditions. Following these requirements ensures the suitability of signature data for forensic handwriting examination and, consequently, increases the reliability of the associated electronic documents. In spite of rapidly evolving technology, they can serve as a solid basis for understanding and consideration of the optimal use of digitally captured signatures for signing electronic documents.

Past, Present, and Future of the Forensic Use of Fingermarks

Abstract: The focus of this chapter is to describe the forensic uses of fingermarks and fingerprints over the years and their awaited evolution. To do this, past conceptions are combined with the current knowledge status to highlight the overall potential of fingermarks and friction ridge skin patterns. For each application, the main academic and operational challenges are described.

Synthetic cannabinoid receptor agonists and their human metabolites in sewage water: Stability assessment and identification of transformation products.

Abstract: Since their first appearance in 2008, synthetic cannabinoid receptor agonists (SCRAs) remain the most popular new psychoactive substances (NPS) in the EU. Following consumption, these drugs and their metabolites are urinary excreted and enter the sewage system enabling the application of wastewater-based epidemiology (WBE). Knowing the fate of target analytes in sewage water is essential for successful application of WBE. This study investigates the stability of several chemically diverse SCRAs and selected human metabolites under sewage conditions utilizing a combination of liquid chromatography-tandem mass spectrometry and high-resolution mass spectrometry (HRMS). Target analytes included SCRAs with indole (5F-PB-22, PB-22 pentanoic acid), indazole (AMB-FUBINACA, 5F-ADB, 5F-ADB dimethylbutanoic acid), carbazole (MDMB-CHMCZCA, EG-018) and γ-carboline (Cumyl-PeGaClone) chemical core structures representing most of the basic core structures that have occurred up to now. Stability tests were performed using wastewater effluent containing 5% activated sludge as inoculum to monitor degradation processes and formation of transformation products (TPs). The majority of investigated SCRAs, excluding the selected human metabolites, was recalcitrant to microbial degradation in sewage systems over a period of 29 days. Their stability was rather controlled by physico-chemical processes like sorption and hydrolysis. Considering a typical hydraulic in-sewer retention time of 24 hours, the concentration of AMB-FUBINACA decreased by 90% thus representing the most unstable SCRA investigated in this study. Among the ten newly identified TPs three could be considered as relevant markers and should be included into future WBE studies to gain further insight into use and prevalence of SCRAs on the drug market.

Special Session: Physical Attacks through the Chip Backside: Threats, Challenges, and Opportunities

Abstract: This paper reviews the evolution of a powerful class of physical attacks against integrated circuits (ICs), developed initially for performing failure analysis (FA) from the IC backside. Over the last two decades, several publications have demonstrated the effectiveness of these techniques in bypassing the IC protection schemes and extracting the stored assets inside secure ICs. In this work, we take a fresh look at such hardware attacks from three different perspectives. First, we will discuss the potential threat of the attacks against modern technologies and demystify a set of wrong beliefs about the attacks’ complexity. Second, we review some technical challenges of such attacks from a law enforcement agency’s perspective for unraveling crimes and preventing further crimes by criminals involved. Finally, we give an insight into the future development of FA tools and the opportunities for designing effective countermeasures against attacks through the chip backside.

Nonresponse bias when estimating victimization rates: A nonresponse analysis using latent class analysis:

Abstract: The study expands empirical knowledge on nonresponse bias when estimating victimization rates by using latent class analysis (LCA). Based on information about proxy-nonrespondents (hard-to-reach re...

Estimating the Age of Fingermarks: Relevance, Potential Approaches, and Perspectives

Abstract: The age estimation of (latent or visible) fingermarks recovered at crime scenes may be particularly useful to be able to discern traces relevant to the investigated event or to help place a particular event in time. The measurement of physical or chemical changes of fingermark characteristics over time has been proposed as a mean to achieve this goal. However, fingermark depositions are complex matrices that are influenced by many factors besides time, such as donor, transfer, and environmental conditions to cite only a few. Thus, the main challenge resides in the identification of aging parameters that evolve over time with as little influence as possible from such factors. The development of reliable aging models that can be implemented in practice to place fingermarks in time requires the acquisition of large amounts of fundamental data on the aging processes of target compounds, if possible, using versatile and easily available analytical techniques. The importance of the data interpretation stage should not be underestimated either. Thus, while age estimation of fingermarks would be particularly useful for crime reconstructions or as evidence in court, much more information is currently needed on the aging of natural fingermarks. A research cycle is proposed to address this issue in a more systematic manner, and several cases in which fingermark dating was either attempted or debated are discussed from a forensic perspective.

Möglichkeiten und Grenzen der forensischen DNA-Analyse unter dem Gesichtspunkt verschiedener Szenarien zur Spurenentstehung

Abstract: Die forensische DNA-Analyse hat sich in den letzten Jahrzehnten mit zunehmender Sensitivitat und gleichzeitiger Standardisierung der Methodik zu einem festen Bestandteilteil der Strafverfolgung entwickelt. Dank der standigen Verbesserung der Analysemethoden ist es zwischenzeitlich nahezu selbstverstandlich, immer kleinere, latente DNA-Spuren erfolgreich zu typisieren. Dies fuhrt mehr und mehr zu einer Verlagerung der Sachverstandigentatigkeit in die Bewertung komplexer Spurenszenarien im Rahmen einer Hauptverhandlung: Anstelle der Zuordnung einer Spur zu einer Person ruckt die Spurenentstehung bzw. die Moglichkeit eines DNA-Transfers ohne Bezug zu einer strafrechtlich relevanten Handlung in den Fokus der Diskussion. Aus Sicht der Deutschen Spurenkommission erscheint es notwendig, das Bewusstsein fur mogliche alternative Szenarien zur Spurenentstehung zu scharfen. Zur Einordnung eines DNA-Ergebnisses in den Kontext der ubrigen Sachbeweise eines konkreten Fallszenarios wird im vorliegenden Beitrag das bereits in der internationalen Fachliteratur seit geraumer Zeit etablierte Konzept der „Hierarchie der Hypothesen“ vorgestellt. Daruber hinaus werden die wissenschaftlichen Grundlagen zur Bewertung alternativer Szenarien des DNA-Transfers erlautert und gleichzeitig die Moglichkeiten und Grenzen einer gutachterlichen Stellungnahme dargestellt.