Forensic Sci., Volume 3, Issue 4 (December 2023) – 9 articles

Sexual assault kits are the standard method for collecting and preserving sexual assault evidence. During the sexual assault examination, swabs are commonly used to collect bodily fluids as sexual assault evidence from the vagina, anus, mouth, and skin. The type of fiber swab used during collection can greatly influence the recovery of the substrate. In cases where lubricant residue may be present, it would be useful to identify the swab type that would be the most efficient in the collection of lubricant residues. In this study, four types of swabs with different fibers (i.e., cotton, polyester, rayon, and foam) with sexual lubricants present, were extracted in various solvents. The extracts were analyzed using attenuated total reflectance Fourier-transform infrared (ATR-FTIR) and Raman spectroscopy. The Pearson correlation coefficient (PCCs) test was applied to determine a pairwise comparison between swab lube extracts and the standard lubricant reference. Visual comparisons of the lubricant reference, blank fiber swab, and the fiber lubricant extract were used to determine peak overlap, significance, and matrix interference. Full article

Postmortem interval (PMI) estimation constitutes a challenge for forensic anthropologists. The application of the luminol technique as a preliminary test for PMI estimation is considered easy to use and inexpensive. The objective of our study is to validate luminol chemiluminescence testing through the assessment of intra- and interobserver error. Our sample included 266 human clavicles, with known PMIs ranging between 2655 days and 450 years. After sample preparation, luminol was applied, and the results were observed by two different observers. The intensity of the reaction was measured using a binary scale and a 5-level scale, according to the increasing degree of chemiluminescence. The Kappa statistic was used for the assessment of the intra- and interobserver agreement. The obtained results showed total interobserver error agreement regarding the binary scale and a K = 0.98 (95% CI: 0.97–0.99) regarding the 5-level scale. Additionally, Observer 1 and Observer 2 obtained a 100% agreement concerning the binary scale and a K = 1 (95%CI 0.99–1) and K = 0.99 (95% CI 0.99–1), respectively, concerning the 5-level scale. According to our research, it is possible to conclude that luminol chemiluminescence testing is suitable as a rapid diagnostic test, revealing this method as practically independent of observation error. Full article

The National Institute of Justice reported that current methods for processing sexual assault samples have a high failure rate, with 60 to 80 percent of tested kits unable to produce usable DNA profiles. Even when samples test positive for male DNA, 34 percent of sexual assault kits (SAKs) do not yield recovered male DNA after differential extraction. Less than 30% recovery of available sperm DNA contributes to this low success rate. The SpermX™ method (SX) has been shown to recover 80 percent or more of sperm DNA from sexual assault samples. An interlaboratory evaluation compared SX to standard differential extraction (DE) protocols. Mock samples with known ratios of female epithelial cells and sperm cells were processed using both methods. Results revealed that SX consistently provided CODIS up-loadable DNA profiles, even with as few as 25 sperm cells, whereas DE failed to produce usable results. On average, SX yielded a seven-fold increase in the recovery of unshared male alleles compared to DE. In conclusion, SX outperformed DE in recovering higher quantities of male DNA with minimal female carryover in sexual assault-type samples. This improved success rate in obtaining usable DNA profiles can significantly aid in solving sexual assault cases. Full article

Establishing the manner of death is one of the most challenging tasks for forensic pathologists. We present the case of a 24-year-old woman found dead in the early morning on a flyover. The body was sitting on the ground with the back leaning against a wall. The neck was encircled by a white phone charger cable knotted to the staircase’s handrail. The victim had argued with her boyfriend and tried to jump out of his car while coming home from a wedding party the night before. After that, she left home alone with her phone charger in her hand. Due to self-harm behaviors, the first hypothesis was suicide by hanging. However, the ligature crossed immediately beneath the thyroid cartilage and encircled the neck twice horizontally; the two ends of the cable overlapped, forming a cross-over point in the front-right of the neck. Then, the ligature passed obliquely through the nape, gradually disappearing, forming a gap in the mark. The mark was sharply defined, stiff, yellow, and parchment-like. The investigators performed a three-dimensional scene reconstruction using the Trimble X7 Laser Scanner and the PC-Crash Multibody System. Even though the geometry of the ligature mark in the present case raised doubts about the manner of death, the three-dimensional reconstruction confirmed that the hanging was feasible without any external intervention. Full article

This communication reports the relationship between skeletal age estimates based on the sternal rib ends (using the phase method of İşcan and colleagues, later revised by Hartnett) and the chronological age at the death of 221 U.S. military casualties processed by the Scientific Analysis section of the Defense POW/MIA Accounting Agency and its predecessor laboratories from 2000 to the present. Previously published age ranges for each phase do not provide accurate estimates for a sufficient proportion of the cases for forensic use; as an example, the age ranges that accompany reference cast sets proved accurate for 55% of CIL cases. Combining the published age ranges of İşcan and Hartnett, on the other hand, proved accurate in 99% of the cases. Full article

Motor vehicle accidents are a significant consequence of marijuana abuse. Limitations of its roadside detection and the forensic problems with establishing impairment require innovations that are scientifically achievable. Marijuana abuse currently is at an all-time high in the United States and its physiological effects make it a popular recreational drug that is reported to be a leading cause of preventable morbidity and mortality among the youth in the 18 most affluent nations. The medical benefits of drugs derived from marijuana complicate its forensic regulation. In an extensive 2017 report by The American Academy of Sciences, the evidence for the medical benefits of delta-9 tetrahydrocannabinol (derived from marijuana) were stated to be conclusive or substantial for the treatment of chronic pain in adults, as an antiemetic for treatment of chemotherapy-induced nausea and vomiting, and for improving patient-reported multiple sclerosis spasticity symptoms. The benefits from treatment for many other medical conditions were inconclusive or absent. The evidence is clear that safely driving a motor vehicle is significantly impaired while under the influence of marijuana. However, there is no roadside forensic test that reliably detects impairment, and there is an urgent need for such to protect the public while insuring the legal rights of users. There is strong societal pressure to relax marijuana’s forensic regulation, including removing it from Schedule I of the Controlled Substances Act. Artificial intelligence (AI) should be implemented with appropriate human control to resolve controversies. Full article

Introduction: Three tiny bones compose the human ossicular chain: malleus, incus and stapes. Also known as auditory ossicles, they are united by joints in the middle ear cavity of the petrous part of the temporal bone. Completely developed two years after birth, the ossicular chain is involved in the physiological process of hearing, by which sound waves from the environment are converted into electrochemical impulses. In the last 500 years, most studies have focused on the morphogenesis, morphological variability and clinical pathology of the ossicular chain, whilst only a few studies have added relevant knowledge to anthropology and forensic science. The auditory ossicles and the enclosing petrous bone are some of the hardest in the human skeleton. This is reflected in a relative resistance to fire and in the possibility of preservation and fossilization in millions of years. Materials and Methods: The literature and four present-day forensic cases were included in studying the postmortem loss of the auditory ossicles in skeletal or decomposing remains. Results indicate that it can be ascribed to their destruction or physical displacement, by either macro-micro-faunal action and/or any other natural or artificial disturbance. Discussion: Physical displacement is closely connected to the depositional environment of the skeletal remains, such as burial, entombment (sarcophagus, coffin, vault…), submersion or exposure to natural elements. Auditory ossicles can be recovered in situ, or very close to their anatomical location, when the skeletal material has been involved in an archaeological excavation. In the case of accessible or disturbed remains, scavengers may remove the tiny ossicles and/or they can slip out of the middle ear cavity following skull movements. Entombment offers effective protection against the displacement of the auditory ossicles, whereas aquatic submersion and aquatic movement almost invariably displace them. Conclusion: the preservation of the human auditory ossicles should be critically considered in the comprehensive context of any forensic investigation on human remains since it can assist the reconstruction of their taphonomic history. Taphonomic histories of remains can add crucial information to forensic investigations (e.g., the Post Mortem Interval, PMI). The aim of this study, limited by scarce relevant literature, is to discuss the potential role of the ossicular chain, detected by postmortem imaging techniques, as a taphonomical indicator in decomposing and/or skeletonized bodies. Full article

Interpersonal violence is a rising issue in global society and new approaches are being sought to combat the problem. Within this context, expanding forensic techniques to better document violent crime scenes is critical for improving and acquiring legal evidence, such as proving or tracing contact between victims and suspects. This project aims to demonstrate the potential for forensic investigations in the context of interpersonal violence using a field-based reflective spectroscopy approach. For this, a common cosmetic, Wet‘N’Wild “Color Icon” blush in the shade “Pearlescent Pink”, was mineralogically characterized using transmission electron microscopy and powder X-ray diffraction and subsequently investigated via reflective spectroscopy on a variety of common substrates. Differing amounts of the cosmetic product, ranging from 0.001 g to 0.075 g, were applied to a variety of substrates using a simple push method to simulate forcible contact and material transfer. Substrates included a pine wood block; (calcareous) sand from Tulum, Mexico; Ottawa sand; tile; Pergo wood; linoleum; closet material; carpets; and fabrics. The reflective spectra of cosmetic–substrate combinations were measured via an ASD FieldSpec 4 Hi-Res spectroradiometer. The Wet‘N’Wild cosmetic was reliably detected on various substrates relevant to crime scenes. Minor amounts (as low as 0.02 mg/mm²) could be detected, and average limits of detection of 0.03 mg/mm²) were achieved; however, a calcareous sand (Tulum) had a high level of detection (>0.38 mg/mm²), suggesting that further investigation is needed for more complex sand substrates. The use of the ASD spectroradiometer as a forensic tool within the context of crime scene documentation shows promise. Future work should expand the characterization of cosmetic materials across a broad range of substrates and consider systematic studies of specific population groups. Furthermore, combining this approach with hyperspectral imaging at crime scenes is a promising future direction for crime scene documentation. This work therefore demonstrates a novel method for investigating cosmetics within the context of interpersonal violence and provides a foundation for future laboratory and field work using the ASD FieldSpec 4 and hyperspectral imaging systems. Full article

Forensic geoarchaeology provides a comprehensive and interdisciplinary approach to investigating crime scenes. This field combines the techniques and methods of archaeology, geology, geophysics, and remote sensing, to provide a more comprehensive picture of the events that have occurred at a site. Forensic geoarchaeologists can not only provide valuable information about the context of a crime scene but also help reconstruct past events and collect relevant information about missing persons. Moreover, the use of geospatial technologies and the analysis of evidence together with a vast range of scientific methods and techniques help forensic geoarchaeologists provide compelling and reliable evidence before courts and law enforcement agencies. Although some reticence still prevails among Italians about recognizing forensic geoarchaeology as a fundamental discipline vis-a-vis crime scenes, the recognition of its vital significance is growing in Italy, thanks to the decision of the Italian Standards Organization (UNI) to standardize it alongside other fields of criminalistic expertise. Full article