Journal of forensic sciences最新文献

Three-dimensional (3D) measurement systems for firearm forensics are becoming more prevalent in forensic laboratories, and these instruments are typically coupled with algorithms to assist firearm examiners with comparisons. Due to differences in firearm feature reproducibility on different types of ammunition, comparison algorithms need to be tested utilizing a variety of ammunition brands. For this study, 30 shots were fired, utilizing six common ammunition brands, from each of the 10 casework firearms for a total of 300 cartridge cases. All cartridge cases were scanned on a Cadre Forensics TopMatch-GS 3D desktop system and compared using Cadre's breech face and firing pin aperture shear algorithms for a total of 44,850 comparisons. Receiver operating characteristic (ROC) curves and the area under the curve (AUC) were used to quantify the performance of the algorithms when comparing within and between ammunition brands. Same ammunition brand comparisons (AUC = 0.964) performed statistically significantly better (p = 0.0075) than different ammunition brand comparisons (AUC = 0.944). Overall, the results generally indicated greater reproducibility of characteristics from a firearm when the ammunition in a comparison is the same, however, Cadre's algorithms demonstrated excellent overall discrimination between same and different-source comparisons regardless of ammunition brand (AUC = 0.946). Additionally, score thresholds were evaluated for easier interpretation of what algorithm results mean for practitioners, where 68.6% of same-source comparisons resulted in a similarity score greater than 0.5. These results should assist the field in moving toward the use of algorithms to assist examiners in casework comparisons.

Early detection of submerged bodies is essential to increase the possibility of recovery. Different water bodies present different challenges, particularly rivers and the ocean, where chances of detection are vastly reduced. Modern recreational fish finders incorporate multiple sonar technologies, including Sidescan sonar, at high-frequency resolutions, similar to commercial units. Recreational units are widely available and usually hull-mounted, allowing them to be utilized on almost any vessel in shallow and difficult to navigate environments. Recreational fish finders are currently an untapped resource which may assist search teams with the early detection and recovery of human remains submerged in shallow water (<20 m). This research investigated the efficacy of a modern recreational fish finder attached to a kayak to detect human proxies and living human volunteers submerged at shallow depths in (1) two indoor freshwater environments and (2) two outdoor environments (a freshwater lake and a nearshore coastal environment). Results demonstrated that recreational fish finders can detect human bodies submerged in both fresh and saltwater contexts at shallow depths within the water column and on the water bottom. Recreational units equipped with Sidescan sonar (800 kHz) provided the necessary resolution for underwater body detection at shallow depths. These sophisticated sensors are currently used by recreational boaters and anglers, and offer the opportunity to increase the eyes in the water not just by search and recovery teams, but by the public itself.

Single view metrology poses a persistent challenge in extracting accurate quantitative information from individual images or video frames within the realm of forensic video analysis. Methods such as reverse projection, projective geometry, and photogrammetry have been used in the past with success but require validation and understanding of the limitations of each method. This study aims to conduct a preliminary validation of the subject height estimation feature in Amped FIVE software, which relies on the principles of single view metrology. A group of 14 individuals assumed an upright posture at distances of 2.4 m, 5.4 m, and 10 m away from two security cameras with different resolutions 4k (3840 × 2160) and HD (1920 × 1080). Prior to recording, participants' heights were measured but were not provided to the researcher in this study until after the analysis was completed. A height scale with clearly marked black and white graduations was used as a control. Height estimations were subsequently obtained using the Measure 3D tool in Amped FIVE software. On average, the overall error was found to be approximately ± 1.3 cm with a standard deviation of 0.9 cm. This study shows that Amped FIVE can provide accurate height estimates in a controlled environment. Future work should be done to test more difficult scenarios in less-than-ideal conditions.

The inconclusive category in forensics reporting is the appropriate response in many cases, but it poses challenges in estimating an "error rate". We discuss the use of a class of information-theoretic measures related to cross entropy as an alternative set of metrics that allows for performance evaluation of results presented using multi-category reporting scales. This paper shows how this class of performance metrics, and in particular the log likelihood ratio cost, which is already in use with likelihood ratio forensic reporting methods and in machine learning communities, can be readily adapted for use with the widely used multiple category conclusions scales. Bayesian credible intervals on these metrics can be estimated using numerical methods. The application of these metrics to published test results is shown. It is demonstrated, using these test results, that reducing the number of categories used in a proficiency test from five or six to three increases the cross entropy, indicating that the higher number of categories was justified, as it they increased the level of agreement with ground truth.

Aggressive chemicals intended for cleaning pools or unclogging drains contain high concentrations of dangerous compounds, leading to their nefarious use in dissolving human remains in some criminal cases. The use of these readily accessible household cleaners to destroy human remains and hide evidence of a crime presents a considerable challenge for human identification. However, research on the success of recovering DNA from such remains is limited. Therefore, we investigated the effects of submerging partial human remains (including whole heads, forearms, and hands) in five different household products: bleach, Rid-X® septic treatment, lye drain opener, sulfuric acid drain opener, and muriatic acid (hydrochloric acid) pool cleaner. We evaluated the impact of each chemical, focusing on visual changes, DNA recovery, and the potential for successful human identification through traditional STR or mitochondrial DNA analyses. Exposure to all chemicals altered the appearance of the remains, but DNA recovery was still possible across various time periods, up to 28 days. Human remains exposed to bleach, Rid-X®, and lye produced full STR profiles after 4 weeks. Sulfuric acid shortened this time to 3 weeks, while hydrochloric acid, the most damaging chemical, limited full STR profile recovery to just the first 3 days of exposure. This study demonstrates that although differences in the rate of damage occur depending on the amount of tissue introduced, volume of chemical used, and the specific chemical of choice, DNA-based human identification of remains treated with everyday household cleaners is likely, particularly if bone fragments are recovered.

People diagnosed with substance use disorder (SUD) might represent a high-risk subpopulation for New Psychoactive Drugs (NPS) consumption, and hair analysis offers a unique perspective to assess drug prevalence in this population. The present study aims to assess the prevalence of NPS and their co-consumption with traditional drugs of abuse (DoA) in individuals diagnosed with SUD. Hair samples from patients under care at the addiction treatment service of Bologna, Italy, for a diagnosed SUD, were collected during 2023 and analyzed by ultra-high-performance liquid chromatography-mass spectrometry (UHPLC-MS/MS), using a previously validated method. Among the 88 patients included, 95.5% tested positive for at least one substance, of which 88.1% for traditional DoA only, and 11.9% for NPS in addition to DoA. Among the positive samples, patients were found positive for more than two drugs in 67.9% of cases. The combination of DoA and NPS was more frequent in the younger age group (<21-30 years old, compared to 31-70, p = 0.025). Ketamine was detected in 8.0% of all samples, with mean hair levels 49.68 pg/mg (ranging 8.55-81.90 pg/mg) and was frequently accompanied by cocaine (85.7% of cases). Fentanyl was detected in 3.4% of all samples, while, among NPS, buphedrone was the only one detected. Our retrospective study highlights that the consumption of NPS is relatively low compared to other vulnerable or high-risk populations. However, the prevalence of polydrug consumption and the high rate of ketamine-cocaine combination warrant careful monitoring even in this population.

Venous aneurysms are rare, and their incidence is unknown. External iliac vein aneurysms are even more rare with only 50 case reports published from 1950 to 2018. We present a case of an individual who died suddenly from a pulmonary thromboembolic event due to an external iliac vein aneurysm formed by a remote penetrating injury. A 32-year-old male was in Immigration and Customs Enforcement (ICE) custody when he died suddenly. It was discovered during his autopsy that he had an occlusive pulmonary thromboembolism (PE) within the left main pulmonary artery and distal branches of the right pulmonary artery. On additional investigation and postmortem computed tomography, a large saccular aneurysm arising from the external iliac vein was discovered. This aneurysm contained clotted blood, and was determined to be the cause of his PE and subsequent death. Although rarely a source for a fatal PE, venous aneurysms should be considered as a possible source for thromboembolism; their presence may alter the manner of death, given their underlying etiology. This is especially true for young adults with a remote history of trauma near a major venous tributary, as traumatic arteriovenous fistula is a common cause of secondary venous aneurysm. For this case, the manner of death was classified as homicide.

With further development of generative AI, primarily generative-adversarial networks (GAN), deepfakes are gaining in quality and accessibility. While, forensic methods designed for examination of handwriting are often applied to its digital copies, despite being possibly insensitive to cases of GAN-made forgeries (unless methods of digital forensics are co-employed). Approaching this problem from a novel perspective, we have created a translational GAN tasked with generating false handwritten signatures from limited examples, aiming to ascertain whether traditional methods of signature examination will be effective against such forgeries. We have found that traditional methods of handwriting examination are sufficient for identification of discriminative features that could result in rejection of GAN-made forgeries, however, those stemmed mostly from the lesser visual quality of the generated signatures, which could be improved in the future.

Forensic entomology relies on known geographic ranges and seasonal presence of forensically relevant insects. In the Northeastern United States, there is no information on species in the region in early spring. Two forensic entomology workshops took place in April of 2023 and 2024 in Milton, Massachusetts. During this workshop, practitioners were trained in the appropriate collection and storage techniques prior to a practical experience including the collection of insects from pig and rabbit remains. All insects collected were identified down to family or species level. Across both years, Phormia regina (Meigen) (Diptera: Calliphoridae) was the fly consistently colonizing remains and was the oldest immature larvae in all instances. Calliphora vicina (Robineau-Desvoidy) (Diptera: Calliphoridae), Protophormia terraenovae (Robineau-Desvoidy) (Diptera: Calliphoridae), and Muscina stabulans (Fallén) (Diptera: Muscidae) were additional flies co-colonizing remains with P. regina. Other species were found as adults surrounding the remains that included other necrophagous fly species, beetles, and ants. Variation in insects collected between years likely due to high temperature variation. This documentation of species provides context to forensically related flies expected in Eastern Massachusetts and provides research directives in the region.

Lophophora williamsii, known for mescaline synthesis, has raised legal and ethical considerations. However, L. williamsii specimens that do not contain mescaline have been recently identified, necessitating the development of techniques to differentiate between mescaline-positive and mescaline-negative groups. Genetic markers have been explored to differentiate these specimens, complementing gas chromatography/mass spectrometry analysis. Here, we used a single-molecule real-time polymerase chain reaction to generate a full-length L. williamsii transcriptome and elucidate the mechanisms underlying mescaline biosynthesis. In total, 2,839,819 base pairs of highly accurate long reads were obtained using PacBio Iso-Seq and 70,945 unigenes were obtained through transcriptome sequencing. Known genes involved in the mescaline biosynthetic pathway were confirmed in the L. williamsii transcriptome, including 6 genes encoding tyrosine decarboxylases, 1 encoding tyrosine/DOPA decarboxylase, 215 encoding O-methyltransferases, and 129 encoding hydroxylases. Gene Ontology analysis revealed 2903 biological processes, 695 cellular components, and 1766 molecular functions. The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed two biosynthetic pathways, namely, phenylpropanoid and isoquinoline biosynthesis, associated with mescaline biosynthesis. To investigate genetic differences based on the presence of mescaline, Illumina Nova sequencing was conducted. The expression levels of genes involved in mescaline biosynthesis were compared to establish a candidate gene pool based on the presence of mescaline. Subsequently, functional annotation was performed on the identified candidate genes using a genetic database derived from PacBio sequencing. These findings underscore the need for a re-evaluation of forensic methods and legal regulations concerning newly identified L. williamsii specimens.