Filter feature selection for unsupervised clustering of designer drugs using DFT simulated IR spectra data

The rapid emergence of novel psychoactive substances (NPS) poses new challenges and requirements for forensic testing/analysis techniques. This paper aims to explore the application of unsupervised clustering of NPS compounds' infrared spectra. Two statistical measures, Pearson and Spearman, were used to quantify the spectral similarity and to generate the affinity matrices for hierarchical clustering. The correspondence of spectral similarity clustering trees to the commonly used structural/pharmacological categorization was evaluated and compared to the clustering generated using 2D/3D molecular fingerprints. Hybrid model feature selections were applied using different filter-based feature ranking algorithms developed for unsupervised clustering tasks. Since Spearman tends to overestimate the spectral similarity based on the overall pattern of the full spectrum, the clustering result shows the highest degree of improvement from having the non-discriminative features removed. The loading plots of the first two principal components (PCs) of the optimal feature subsets confirmed that the most important vibrational bands contributing to the clustering of NPS compounds were selected using NDFS feature selection algorithms.

Computer Forensic Using Photorec for Secure Data Recovery Between Storage Media: a Proof of Concept

Data plays the important role, so that data recovery and data security be prioritized. Computer users often lose their data due to personal errors or by attacks. Digital forensics has one sub-field called computer forensic, which has an important role in the process of secure data recovery. USB Flashdisk as the most widely used storage media has a probability of data loss. It is necessary to do computer forensic actions, especially secure data recovery, on it so that it can restore data securely to other media while protecting it by giving privilege root. In this research, computer forensic testing the 2781 files of various data formats that were erased on a 32 GB USB flash drive using Photorec. The media for collecting data recovery results using an Intel computer, 2 GB RAM, 1.8 GHz processor, the Linux operating system Xubuntu 20.04. Testing is carried out following the test scenarios that have been designed, then observed, recorded, and analyzed. Photorec places recovery data in 6 recup_dir subdirectories. Test results and analysis of the test results show that Photorec is a reliable tool for computer forensic, especially secure data recovery because it can restore 100% of data, accompanied by privilege root for all data recovery results, so they cannot be changed and deleted by an end-user without granted access.

The Link Between the SAMFE and Police Perceptions of Victim Credibility

While research has documented the evidentiary significance of sexual assault medical forensic exams (SAMFEs) to case processing, there has been less focus on SAMFEs’ relevance to extralegal case characteristics. This study, through focus groups with police officers and prosecutors, illuminates the link between two important case processing factors: the SAMFE and perceptions of victim credibility. The majority of respondent narratives about the utility of the SAMFE point to how it strengthens or weakens perceptions of victim credibility. This link points to the SAMFE’s important role in early case processing before investigators send DNA evidence for forensic testing.

Accelerated aging of forensically relevant biological materials on swabs

The preservation of DNA in biological samples is important for forensic testing, as samples can be tested years or even decades after collection. Generally, the DNA within biological evidence is stable over shorter time frames but can degrade over extended periods. In this work, we evaluated accelerated aging as a method to reduce the duration of studies examining the stability of DNA in forensic evidence-type samples. Evaluation of the DNA extracted from cells stored at 37 and 50°C for 194 or 79 days, respectively, showed similar quality metrics to cells stored at 25°C for 548 days.

Animal Forensic Genetics

Animal forensic genetics, where the focus is on non-human species, is broadly divided in two: domestic species and wildlife. When traces of a domestic species are relevant to a forensic investigation the question of species identification is less important, as the material comes from either a dog or a cat for instance, but more relevant may be the identification of the actual pet. Identification of a specific animal draws on similar methods to those used in human identification by using microsatellite markers. The use of cat short tandem repeats to link a cat hair to a particular cat paved the way for similar identification of dogs. Wildlife forensic science is becoming accepted as a recognised discipline. There is growing acceptance that the illegal trade in wildlife is having devasting effects on the numbers of iconic species. Loci on the mitochondrial genome are used to identify the most likely species present. Sequencing the whole locus may not be needed if specific bases can be targeted. There can be benefits of increased sensitivity using mitochondrial loci for species testing, but occasionally there is an issue if hybrids are present. The use of massively parallel DNA sequencing has a role in the identification of the ingredients of traditional medicines where studies found protected species to be present, and a potential role in future species assignments. Non-human animal forensic testing can play a key role in investigations provided that it is performed to the same standards as all other DNA profiling processes.

Ethanol Biomarker Testing and Challenges: Lessons Learned From a College of American Pathologists Proficiency Testing Survey

Context.— Clinical and forensic testing for ethanol biomarkers including ethyl glucuronide (EtG) and ethyl sulfate (EtS) is used to discern alcohol use from abstinence. These markers can be key in major decisions including transplant eligibility or retaining licensure after alcohol misuse. Accuracy, precision, and recognition of the implications of reporting cutoffs are all essential for correct interpretation. Objective.— To evaluate trends in testing for EtG and EtS, including how laboratories perform testing and how comparable participant results are. Design.— The study examined the College of American Pathologists' ethanol biomarker proficiency testing survey from 2013 to 2019. Trends in methodology, reporting cutoffs, and participant performance were evaluated for qualitative and quantitative EtG testing and for quantitative EtS testing. Results.— There was little consensus in reporting cutoffs, which ranged from 10 to 1000 ng/mL for EtG and 10 to 1500 ng/mL for EtS. Although median EtG and EtS compared well with target concentrations, individual participants' results varied widely. For quantitative enzyme immunoassay, accuracy and precision were best in EtG challenges less than 1500 ng/mL. For EtG or EtS by mass spectrometry, overall accuracy was good over a wide concentration range, but variability between participants was high. Approximately 10% (409 of 4059) of results were unacceptable, which for mass spectrometry corresponded to more than 35% above or below the group mean. Conclusions.— Although many participants performed well, there was insufficient consensus in reporting cutoffs and a consistent fraction of laboratories failed to achieve survey standards. Guidelines for assay performance and reporting could greatly benefit laboratories and end users.

Identifikasi Bukti Forensik Jaringan Virtual Router Menggunakan Metode NIST

The evolution information technology has led to the growth of virtualization technology. Router OS is the operating system of the Mikrotik Router, which supports virtualization. Router Os virtualization technique which is easy to run is a metarouter. Metarouter provides benefits such as, building virtual servers, virtual machines, network topology and savings cost. As an object of research, Metarouter introduces challenges to digital forensic investigations, both practitioners and academics. Investigators need to use methodology and tools in order to prove the perpetrators of crimes. This study uses the Windump forensic tool as a means of recording network traffic activity. Network Miner and Wireshark as an analytical tool for identifying digital evidence. The use of the National Institute of Standard and Technology (NIST) method which collection, examination, analysis and reporting, can be repeated and maintained with the same data. Based on experiments with virtual router network traffic testing, the system built has succeeded in obtaining digital evidence, either by direct or indirectly. The system scenario that has been planned succeeded recording 220494 packages, but by the Windump, it is automatically divided into 9 (nine) parts of the package which are Buktidigital0 to Buktidigital8. The inspection stage produces evidence that has been verified by Wireshark and Network Miner. The analysis stage proves that there were attacks carried out by addresses 192.168.10.10 and 192.168.234.10. Based on the results of forensic testing, the use of the NIST method on a forensic system that has been built with a virtual router object can be used by investigators to identify evidence of cyber-attacks.

Wildlife crime in Australia

Wildlife crime is on a massive scale by whatever metric is used. The illegal trade in wildlife and related products is leading to the decline and extinction of many iconic species from rhino to tigers. Almost all countries are signatures to CITES and therefore should enforce national legislation if alleged infringements of trade of wildlife occur. No country is immune from this illegal trade although countries like Australia have their own specific wildlife crimes. Australia is home to many reptilian, amphibian and avian species that are highly prized, predominantly as pets. Collection of protected species from the wild is illegal in all jurisdictions yet policing remote areas of the outback, where so much of the native endemic fauna and flora lives, is nearly impossible. The illegal international trade in these species is highlighted by two case studies provided in this review. A further case highlights the issues of each of the six states of Australia having separate legislation, which is compounded when wildlife crime can be inter-state crime. Australia is one of the few countries having an institute, based at the Australian Museum, with an accredited wildlife forensic science laboratory and therefore the capability to undertake forensic testing of seized samples. One way to reduce wildlife crime may be by educating those who buy illegally seized products that there is a direct connection between the dead animal from which it came and the devasting effect this purchase has on the environment.

Development of High Friction Surface Treatment Prescreening Protocols and an Alternative Friction Application

The use of high friction surface treatments (HFST) has become increasingly popular to help improve roadway friction properties and reduce the number of lane-departure and breaking-related accidents. Conventional HFST installation consists of applying an epoxy-resin material to an existing roadway surface and “gluing” a hard, highly angular fine aggregate to the roadway surface. When constructed correctly, skid resistance values (SN40) are often measured in the upper 60s and 70s. However, this functional overlay does not come without potential issues. Performance and service life is strongly dependent on the quality of the construction process, as well the quality of the substrate, which is often difficult to assess in situ. The paper summarizes the forensic testing of three HFST installations in New Jersey—one performing well and two showing premature failure. Testing procedures and preliminary criteria for existing asphalt pavement surfaces were developed to address whether or not epoxy-resin HFST is a viable option. Additionally, the paper summarizes the development and forensic testing of a potential alternative to the epoxy-resin based HFST application. This alternative surface, called a high friction chip seal (HFCS), incorporates the same hard, highly angular fine aggregate but using asphalt binder as the “gluing” medium within the chip seal application process. Three different aggregate sources were evaluated using the HFCS application on Rt 68 in New Jersey. Laboratory testing of the aggregates, as well as field measurements of the test sections, were conducted. It was found that HFCS could be a potential alternative for areas where premature HFST failure is a concern.