Forensic Science International: Reports最新文献

Introduction

Humerus is a long bone that contributes significantly to the total height of an individual. It is sexually dimorphic and is a well-preserved bone postmortem. Height and sex are essential in establishing one's identity and can be estimated from long bones when standing height cannot be easily obtained. Previous studies report that sex and height are population-specific. Hence, the present study sought to establish the relationship between percutaneous humeral lengths and height and formulate models for height and sex determination for the Ghanaian population.

Materials and methods

Measurement of standing height and percutaneous humeral lengths were taken from 286 Ghanaian consented participants with no noticeable lower and upper extremities traumas or pathologies. The data was analysed using Microsoft Excel 2013 and SPSS version 23.0 edition. Correlation analysis was done to determine the correlation of the percutaneous humeral length with height, linear regression and binary logistic analyses were used to derive equations for predicting height and sex from percutaneous humeral length. An independent samples t-test was used to determine the means between males and females, left and right percutaneous humeral lengths.

Results

There was a strong positive correlation between standing height and left (r = 0.774) and right (r=0.759) humeral lengths. The left humeral length regression equation was a good height estimator in males (75.4%) and females (71.%). The left and right humeral lengths best predicted the sex for the population, with an accuracy of 78.0% and 77.8% for males and 53.8% and 54.6% for females, respectively.

Conclusion

This study has added to the limited data on the use of percutaneous humeral length as a substitute for the determination of standing height and sex in the Ghanaian population, and it is also a significant identification tool which can be employed in the field of forensic anthropometry.

In Korea, most drivers equip their vehicles with a black box camera, used to estimate the speed of the vehicle in case of traffic accidents such as car-to-car collisions, single-car accidents, and car-to-pedestrian accidents. Traditionally, speed estimation using the camera video has been done by using the distance between the road lane, surrounding structures, etc.

However, when the following vehicle collides with a stationary leading vehicle or barrier, and no road lanes or structures are visible around the driving path in the black box camera video of the following vehicle, the speed of the following vehicle could be just estimated according the deformations on the collided vehicles or objects.

Therefore, in this study, when a vehicle collision occurs, a virtual parallel line is drawn between the leading vehicle and the following vehicle in the black box camera image of the following vehicle and analyzed geometrically to estimate the distance and the speed of the following vehicle.

After the vehicle collision experiment, the speed was estimated using the method proposed in this study using the captured black box video. As a result, it was confirmed that the accuracy was high when the collision speed was low. So The method proposed in this study is expected to be used to estimate collision speed in the cases of low impact speed in the rear end collisions.

The foramen magnum (FM) occupies a well-protected position, making it particularly intriguing for forensic research. The necessity for methods to estimate sex from cranial fragments becomes evident when only a partial skull is available for identification. The objective of this study was to assess sex differences in anthropometric measurements, including the length of the foramen magnum (FML), width of the foramen magnum (FMW), foramen magnum area (FMA), and circumference, with the aim of developing a binary logistic regression model in Thai cadaveric donors. Sixty adult dry skulls underwent both intraclass and interclass correlation analyses. Subsequently, 240 adult dry skulls of known sex (120 males and 120 females) were meticulously measured and analyzed to determine the optimal threshold for sex determination. Morphometric analysis of the FM was carried out using vernier calipers, and the area of the FM was precisely calculated. The FML, FMW, FMA, and circumference were all found to be significantly larger in males than in females. Furthermore, FM circumference exhibited an AUC (Area Under the Curve) value of 0.908, signifying it as an excellent parameter for sex discrimination. Lastly, binary logistic regression was executed. Significant sex differences in FM circumference were consistently observed, demonstrating an accuracy of 81.62% when validated in 120 dry skulls.

The human microbiome comprises trillions of microbial cells, primarily bacteria, found in places such as the gut, oral cavity, and skin. The human microbiome holds significant potential in forensic investigations, with important applications in post-mortem analysis, geographical identifications, sexual assault cases, and personal identification. The human microbiome displays significant variations, which can be utilized to distinguish individuals based on their distinctive microbial signatures, thus facilitating identification. Microbiome composition varies geographically and can be explored for identification of individuals’ origin or location. In addition, changes observed in microbial composition during different stages of decomposition can provide valuable insight into the time and location of death which can assist in forensic investigations. However, the use of microbiomes in forensic investigation is still developing and under-utilized, especially in the developing world. This article reviewed emerging microbiome analyses, their strengths, limitations, and potential for future research in forensic investigations. In particular five microbiomic forensic applications were looked at; postmortem analysis, geographical identification, sexual assault cases, bite marks and personal identification. Despite challenges and limitations associated with storage sensitivity, limited samples, and lack of standardization, the use of microbiomes in forensic investigation is quite promising. However, future research should focus on more extensive and standardized studies to overcome these challenges and fully harness the potential of the human microbiome in forensic investigations, enabling its practical application in various forensic scenarios.

Introduction

Isolated fractures of the cricoid cartilage are rare. They are caused by violent trauma such as road traffic accidents, sports’ accidents and also assaults.

Observation: We report the case of a 39-year-old male who presented a displaced bifocal posterior fracture of the cricoid cartilage with a retropharyngeal haematoma responsible for the narrowing of the subglottic airway of around 70% following manual strangulation. He was intubated by nasofibroscopy then surgery was attempted to reduce one of the posterior fragments coupled with tracheotomy, with no success. The tracheostomy was kept in place for a total of three months and the subject was kept hospitalised for two months, due to recurring pulmonary abscesses requiring antibiotic treatment and drainage. On the last follow-up consultation, over one year after the trauma, persisted vocal weakness, exertional stridor, asymmetric positioning of the right arytenoid and laryngeal stenosis of around 15%.

Discussion

We found 57 cases of cricoid fractures in the literature review. The primary manifestations of such fractures are dyspnoea, dysphonia and pain. The treatment most often consists in securing the airway by tracheostomy or intubation, however surgery can prove necessary. The main complication is laryngeal canal stenosis by granulomatous scar reaction. From a medico-legal point of view, cricoid fractures are considered by some authors as a potential indicator of homicide given the great force required to achieve this type of fracture, or at the very least, should raise suspicion of third party involvement. In the case of forensic autopsies, a meticulous examination is required given the fact that this cartilage is well sheathed inside the various surrounding structures. In forensic expertise, the potential complications and sequelae of these fractures should be taken into account.

Conclusion

Fractures of the cricoid cartilage are important for both clinician and forensic physician to be aware of, because of potential complications and sequelae, and because this type of trauma should raise suspicion of third-party involvement.

Testing of evidence in an alleged sexual assault case not only seeks to address the question of who was involved, but also looks to answer the question of what biological source provided the DNA. It can be difficult to obtain positive serological data on challenging samples such as laundered items, low-level DNA samples, or sexual assault kit swabs obtained after a prolonged interval from the time of assault. In the absence of confirmatory serological results, an expert witness often cannot speak to the biological source of the DNA. In order to determine quantitation thresholds which could be used to deduce the presence of spermatozoa (sperm) within a sample, we evaluated the fractionation of male DNA utilizing our laboratory’s differential extraction method. Study samples included serial dilutions of semen and semen/saliva mixtures, post-coital and laundered samples as well as casework data from 1,729 samples that were processed using a differential extraction. Based on this data, it was determined that a sample which had at least 200 picograms of male DNA and at least 10% of the total male DNA in fraction 2 (F2, also known as the sperm-enriched or sperm fraction) could be reported as positive for the presence of sperm. No false positive results were obtained from the study-generated samples when using these thresholds to infer the presence of sperm. Additionally, samples that contained sperm, but were negative using traditional serological methods, could be detected. However, not all sperm-containing samples fractionated above both thresholds; therefore, serological testing may still be necessary to minimize false negative results. The thresholds developed here, proved reliable to deduce the presence of sperm in real casework samples.

In this study, we compare the performance of a simple PVP extraction method with a commercially available and widely used kit for recovering DNA from adhesive tapes. This novel method shows almost 60% higher DNA recovery from blood deposits on SceneSafe Fast™ minitapes when compared to the PrepFiler™ BTA Forensic DNA Extraction Kit. We also demonstrate how a simple modification of the magnetic bead-based purification step can lead to better recovery and removal of PCR inhibitors.

Background

Individualisation is essential when assessing physical evidence that is discovered at a crime scene to connect the evidence to a suspect or victim. Many studies on the identification of an individual from various evidence types have been conducted across the globe. Once identified, a person's sex completes 50% of the individualisation process, which assists the investigator in leading the investigation in a specific direction by narrowing down the pool of suspects. The current study intends to ascertain an individual's sex, be it male or female, based on footprint evidence, which is a highly neglected research area. The present study is part of an anthropometrical research in which seven different footprint measurements, specifically lengths and widths, were recorded and statistically assessed to determine a person's sex from inked bilateral footprints of 132 individuals (61 males and 71 females) aged 18–50 years, who were born in South India.

Results

The t-test scores show that the right footprint parameters are similar to the left footprint, except T1 (Length between the pternion and the first toe anterior point) and B1 (Total Ball Breadth) in females. T4_R (Length between the pternion and the fourth toe anterior end of the right foot) exhibited the strongest correlation with sex. In contrast, HB_Index_R (Heel ball index of right foot) exhibited the weakest correlation. The male and female footprints achieved 77% and 93% accuracy rates, respectively.

Conclusions

A person's sex can be established, to a satisfactory degree, with the help of individual footprint measurements. Further studies can develop population-specific footprint standards to help investigators hasten the identification process.

In this study, population data were generated from South Africans using the Investigator® 24plex GO! Kit (QIAGEN, Hilden, Germany). Participants represented the four major population groups in South Africa, with self-reported ancestral origin being African (n = 208), European (n = 213), Indian/Asian (n = 103) or Admixed (n = 209). Allele frequency data and forensic parameters were calculated for each population group using Arlequin (v.3.5.2.2) and FORSTAT (v1.0). TPOX had the lowest discrimination capacity for all population groups, except for the African population group where THO1 was the least informative. SE33 had the highest discrimination capacity for all population groups (>0.98), with 38 different alleles observed in the Admixed population group. Samples exhibiting novel alleles or anomalies underwent massively parallel sequencing using the ForenSeq™ DNA Signature Prep kit, which confirmed the following results: one null Y allele at Amelogenin, ten instances of TPOX tri-allelism and four novel micro-variant alleles. An additional four novel alleles in SE33 were observed but remain unconfirmed, due to SE33 not being included in the ForenSeq™ DNA Signature Prep kit. Moreover, nine individuals had an allele 8 or 9 at D1S1656, where the peaks for these alleles occur before the D1S1656 marker range on the electropherogram and showed as a peak within the DYS391 marker. Although this observation was rare overall (1.2%), these nine individuals were from three of the four population groups, which motivates for the adjustment of the Investigator® 24plex PCR chemistry to avoid allelic overlap of D1S1656 with DYS391. Overall, these findings highlight the diverse genetic makeup of the South Africa population and accentuate the importance of local population studies.

Within the fields of forensic anthropology and forensic medicine in general, the ability to provide accurate estimates of time since death that minimize error, maximize precision, and consider a multitude of variables is a critical component of all forensic and medicolegal investigations that focus on the identification of human remains and the circumstances surrounding death. In comparison with many forensic cases where date of death is typically unknown, we begin with a known postmortem interval and progressively assess, through external testing measures (temperature, skin elasticity and skin color changes) followed by photography and videography, decompositional changes over time. This work seeks to provide well-described cases with documented biological parameters to propose hypotheses for future research. Field team members observe and record any decompositional changes associated with the states of algor, rigor, and livor mortis, as well as progressive changes in skin color and tissue integrity in an environment where variability in climate and ecological factors may vary from case to case. The two cases were followed for 31 (postmortem interval [PMI] 38) and 19 (PMI 27) days in humid subtropical and tropical monsoon Köppen-Geiger classified climatic zones, respectively, where delayed decompositional and putrefactive changes observed are at odds with the anticipated rate and expected suite of biological changes occurring within an indoor permeable setting following clinical death. Within this taphonomic context, we also address the value of describing and documenting postmortem intervals in a closed subpopulation from which some individuals are recognized for exhibiting attenuated decompositional changes. This study emphasizes the importance of addressing understudied and underrepresented regions, climates, and cultural contexts for furthering research into the factors that may contribute to the understanding of the early stages of the PMI period and improve the precision of PMI estimates more broadly.