Massively Parallel Sequencing (MPS) is effective for monitoring the microbial composition of environmental samples. Soil microbial signatures are critical for pinpointing the geographic location of forensic evidence, but standard 16S rRNA methods lack species-level resolution. Targeted sequencing panels, consisting of informative DNA fragments, can overcome this shortcoming and are highly desirable for forensic investigations. To address this, we evaluated three target enrichment methods for metagenomic analysis. First, we used Whole Metagenome Sequencing (WMS) data from 134 soil samples across 46 locations in Poland to extract a set of 200 markers. Using these markers, we created prototype targeted sequencing panels to compare two amplicon capture-based methods (Thermo Fisher AmpliSeq™ and Integrated DNA Technologies xGen™) and one hybridization capture-based method (Roche KAPA HyperPlus). The comparison of the technologies was guided by the results of classification of sample origin by machine learning classifier trained on feature profiles from WMS. The methods were assessed on technical parameters including data quality, reproducibility, sensitivity, and practical implementation for forensic laboratories. The performance and precision varied depending on technology and DNA concentration. The Roche KAPA HyperPlus hybridization capture-based method consistently demonstrated superior performance. Across various DNA input quantities, it showed the highest correlation with WMS data and achieved an exceptional F1 score of 0.94 at 5 ng, significantly outperforming the amplicon-based methods. This indicates that hybridization capture is a more robust and accurate approach for forensic soil microbiome profiling, particularly for low-template evidence, providing a highly reliable tool for predicting geographic origin. • Targeted Massively Parallel Sequencing methods for forensic soil microbial analysis • Targeted sequencing allowed the determination of the place of origin of soil samples • Roche KAPA HyperPlus: the most accurate classification of the soil samples origin.
Since the late 20th century, the field of dactyloscopy has witnessed ongoing attempts to create an examination standard that combines the merits of both numerical and holistic standards while avoiding their drawbacks. In recent years, fingerprint examiners, regardless of the standard employed, have begun to recognize the necessity of incorporating the frequency of occurrence of individual fingerprint minutiae types into examinations. In Poland, the first research on this subject was conducted at the turn of the 1960s and 1970s by Professor Czesław Grzeszyk. The results of said research were published in Problemy Kryminalistyki No. 96 (1972) and for years constituted the basis of knowledge regarding the frequency of various characteristic types. However, due to the severely limited technical capabilities of that time, the results obtained by Professor Grzeszyk may have been subject to significant measurement error. For this reason, fingerprint experts from the Central Forensic Laboratory of the Police replicated the study on the frequency of occurrence of individual minutiae types in the Polish population, utilizing computer software created specifically for this purpose under the „Fingerprint Mapping” project and applying the catalog of fingerprint characteristics currently in force in police forensic laboratories. This article presents an analysis of the results obtained following the „mapping” of 1,104 fingerprint impressions.
This article presents the specific characteristics of Disaster Victim Identification (DVI) operations conducted in the context of terrorist attacks, emphasizing the differences from standard Interpol DVI procedures typically applied during natural or technical disasters not caused by deliberate human action. Key operational aspects are discussed, including conducting DVI activities in a high-risk environment, the need for rapid perpetrator’s identification, priority transmission of high-value identification data, and the social and media pressure associated with terrorist incidents. The article is based on practical experience gained during the international exercise “Urban Disaster 2025” held in Lešť, Slovakia, which enabled practical improvements of procedures dedicated to victim’s identification of terrorism-related disasters.
The development of the digital document authentication technology is making biometric signatures an increasingly common subject of forensic examination. The prerequisite for the reliable identification of their maker is properly collected reference material, whose role, as in the analysis of traditional signatures,remains crucial. In contrast to signatures made on a paper substrate, it is necessary to take into account the specificities of the device and software, such as the surface of the screen, the type of stylus and the data recording parameters. The practice of the Central Forensic Laboratory of the Police shows that samples taken on identical equipment and under identical technical conditions guarantee full comparability with evidence. At the same time, conventional manuscripts have an important supporting role. The growing importance of digitally captured signatures in business requires creating consistent standards for the collection and analysis of test material that would combine the experiences from handwriting examinations with new digital tools.
Since COVID-19 has emerged and become a global health issue, an awareness of wearing face masks has been attentive to prevent the spread of the disease. Face masks that have become a part of daily life, may be encountered at crime scenes and serve as a potential source of DNA for human identification. This study developed a rapid method for obtaining abundant DNA from 3-layer disposable face masks. Ten healthy volunteers were recruited to wear the masks for a period of 2 h. The optimal method for retrieving DNA was determined to be direct cutting of the middle section of the mask's inner layer. The average DNA concentrations from males and females were 0.127 0 ± 0.233 7 ng/μL and 0.069 9 ± 0.107 4 ng/μL, respectively, with no significant difference observed between the sexes (P = 0.286). Furthermore, testing a smaller area (28 cm2) from the mouth-covering region still yielded sufficient DNA for STR genotyping (average 0.025 5 ± 0.021 8 ng/μL). Comparison of the inner and the filter layers revealed that the filter layer contained significantly less DNA (average 0.021 3 ± 0.020 3 ng/μL, P < 0.05). A mockup study was conducted on two female volunteers using six commercial brands of medical, carbon, and super 3D mask types. The results showed that the minimum DNA concentration (0.008 3 ± 0.003 1 ng/μL) extracted from a carbon type is also plenteous for short tandem repeats (STR) genotyping. Finally, mockup samples with low copy number were genotyped and they produced profiles with >19 autosomal STR loci. This suggests that the method was suitable in DNA analysis when a face mask is found as forensic DNA evidence.
