The transfer and persistence of metals in latent fingermarks

In forensic science, knowledge and understanding of material transfer and persistence is inherent to the interpretation of trace evidence and can provide vital information on the activity level surrounding a...

Unusual Application of Insect-Related Evidence in Two European Unsolved Murders

Insect-related evidence must be considered of probative value just as bloodstains, fingerprints, fibers, or any other materials. Such evidence if properly collected and analyzed can also provide useful details in the reopening of old unsolved murders, also called “cold cases”. This paper presents the case of two murders that occurred in two different European countries and remained unsolved for years. The remains of a girl found in Italy 17 years after her disappearance helped to solve a murder that occurred in Britain 8 years prior. The cases were unexpectedly linked together because of the similarities in the ritualistic placing of strands of hair and connections with the suspect. The trace evidence relating to insects and hairs played a relevant role in the conviction of the perpetrator. In Italy, the defense raised the doubt that the strands of hair found nearby the skeletal remains could be the result of insect feeding activity and not the result of a cut by sharp objects. Therefore, it was fundamental to distinguish between sharp force lesions and insect feeding activity on hair. This unusual application of insect-related evidence clearly emphasizes the importance of an appropriate professional collection and analysis of any physical evidence that could be of robust probative value.

Tire Classification by Elemental Signatures Using Laser-Induced Breakdown Spectroscopy

Tire evidence is a form of trace evidence that is often overlooked in today's forensics, while frequently found at crime or accident scenes, usually in the form of skid marks. The pattern of the tire skid mark has been used before to link a tire or car to a scene, but the widespread use of anti-lock braking systems makes this an almost impossible and abandoned route of analysis. With this in mind, using the chemical profile of a tire has potential to link a car or tire back to a scene in which its trace material is found. This study shows the successful use of the elemental profile of tire rubber to classify 32 different samples using laser-induced breakdown spectroscopy, analyzed by principal component analysis combined with linear discriminant analysis. A classification accuracy close to 99% shows the ever-growing use of laser-induced breakdown spectroscopy as a technique of choice for forensic analysis of tire rubber, opening the path for its use as a forensic evidence.

Forensic Applications of Microbiomics: A Review

The rise of microbiomics and metagenomics has been driven by advances in genomic sequencing technology, improved microbial sampling methods, and fast-evolving approaches in bioinformatics. Humans are a host to diverse microbial communities in and on their bodies, which continuously interact with and alter the surrounding environments. Since information relating to these interactions can be extracted by analyzing human and environmental microbial profiles, they have the potential to be relevant to forensics. In this review, we analyzed over 100 papers describing forensic microbiome applications with emphasis on geolocation, personal identification, trace evidence, manner and cause of death, and inference of the postmortem interval (PMI). We found that although the field is in its infancy, utilizing microbiome and metagenome signatures has the potential to enhance the forensic toolkit. However, many of the studies suffer from limited sample sizes and model accuracies, and unrealistic environmental settings, leaving the full potential of microbiomics to forensics unexplored. It is unlikely that the information that can currently be elucidated from microbiomics can be used by law enforcement. Nonetheless, the research to overcome these challenges is ongoing, and it is foreseeable that microbiome-based evidence could contribute to forensic investigations in the future.

VIDROS AUTOMOBILÍSTICOS COMO VESTÍGIOS DE CENA DE CRIME: UMA ABORDAGEM MULTIVARIADA

AUTOMOBILISTIC GLASSES AS CRIME SCENE TRACES: A MULTIVARIATE APPROACH. Glasses are common trace evidence elements in crime scenes, and the analysis of this material can be essential for evaluating different criminal dynamics. This work aimed to analyze the possibility of differentiating and classifying windshield glass using multivariate analysis methods. Automotive glass fragments from different vehicle brands were evaluated according to internal and external faces. We have collected from literature EDXRF (Energy Dispersive X-ray Fluorescence) data for different oxides concentrations. These data were organized in a matrix with 56 samples and nine variables. We applied unsupervised (PCA, Principal Component Analysis) and supervised (SIMCA, Soft Interclass Modeling Classification Analogy) methods. We assessed the classification responses through ROC (Receiver Operating Characteristics). As a result, the PCA indicated the presence of two groups of glasses in three main components. SIMCA verified the unsupervised classification, and the distances and interclass residues parameters were adequate with no outliers. The ROC analysis indicated a sensitivity of 0.793, a specificity of 0.815, and an efficiency of 0.804 for predictions. We concluded that multivariate analysis was successful in discriminating between the internal and external faces of automotive glasses.