Forensic Science International: Reports最新文献

One crucial aspect of a forensic procedure is sex estimation during individual identification. Hand and its remains are usually among the common body parts found in scenes of mass disasters during forensic investigations. Hand outlines are also important in several biomedical fields such as prosthetics, plastic surgery, and ergonomics. This cross-sectional study was done to investigate sexual dimorphism and discriminate sex using hand and hand print dimensions of 283 male and 317 female subjects who were randomly selected. Bare hand measurement and bilateral hand prints were obtained using Vernier caliper, inked pad, and A4 plain paper. Data obtained were analyzed using SPSS version 23.0 IBM. Sexual dimorphism in all the hand dimensions and prints of both hands were observed. The binary logistic regression model showed that in the left hand, bare left-hand breadth (BLHB) was the single best variable to discriminate sex with a percentage accuracy of 69.5 %. Bare right-hand breadth (BRHB) was the best predictor in the right hand with a percentage accuracy of 71.8 %. The predicted probabilities of the binary logistic model (BLR) for the variables that contributed best to the prediction were analyzed using the receiver operating characteristic (ROC) curve. It was observed that the BLHB and BRHB had the highest area under the curve (above 0.5) in the hand and print variables respectively. Sexual dimorphism and sex determination were established in this study using hand dimensions and prints. The BLHB and BRHB were the best sex determinants in this study. Although the accuracies of sex estimation from both hands in this study are low, it does confirm and support previous reports of handbreadth being the best variable for sex estimation.

Synthetic skin produced by SynDaver®, currently used primarily in medical testing and training applications, may be suitable as a surrogate for human skin in forensic investigations. To determine how accurately the company's synthetic skin, SynTissue®, could mimic the mechanical properties of human skin, tests were conducted to measure its elastic modulus and resistance to laceration. Test results were compared to published data acquired from tensile tests conducted on human scalp and impacts with blunt objects on porcine heads. The stress vs strain relation for SynTissue® 8 N corresponded closely to that of the human scalp. Deformations similar to skin lacerations were observed when SynTissue® was subjected to blunt object impacts, at forces in the range of those reported for lacerations of cadaver and porcine heads. However, the published data are insufficient to unequivocally assess the suitability of SynTissue® for forensic investigations of lacerations. Moreover, there are features of the SynTissue® impact deformations that can provide useful information even if the laceration threshold turns out to be lower than that of human skin.

This is a Letter to the Editor in response to Kariks J. Diaphragmatic muscle fibre necrosis in SIDS. Forensic Sci Int. 1989 Dec;43(3):281–91. doi: 10.1016/0379-0738(89)90156-4. PMID: 2613142.

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.

As forensic anthropologists play a larger role in post-mortem examinations, the examination and interpretation of skeletal trauma resulting from sharp, blunt, projectile, and thermal injuries have become of critical importance and may assist in medicolegal death investigations. Although there is a plethora of research on sharp force trauma on bone, at present, there is little research regarding the striations produced by large bladed weapons on bone, whether those striations are weapon-specific, or whether they are the result of sharpening materials and methods. To test whether striations are weapon type specific, this study aimed to examine if different sharpening materials and methods produced different striations on the kerf walls of cut marks on bone produced by machetes. Or, if they do produce the previously identified ‘rolling hill’ striation pattern. Four factory machetes sharpened by the same manufacturer were re-sharpened using a wet stone, a bastard file, and a coarse and medium-grained machine grinder. The bones and casts were subjected to both macro and micro analyses, and the results identified clear differences in the shape of striation ridges and troughs, indicating that striation patterns are not weapon type-specific. The study's findings have opened up a new area of research into weapon types and the analysis of associated striation patterns and may aid in the identification of weapon types and the materials used for maintenance or sharpening, potentially offering additional evidentiary evidence.

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.

Sex estimation models are specific to populations and cannot be generalized due to genetic and environmental variabilities. This retrospective cross-sectional study, conducted between January and September 2023 at the Tamale Teaching Hospital, included 119 (50.9 %) females and 115 (49.1 %) males aged 23–82 years. Measurements, including manubrium length (M), manubrium width (MW), sternal body length (B), combined manubrium and sternal body lengths (CL), corpus sterni width at first sternebrae (CSW_S1), and corpus sterni width at third sternebrae (CSW_S3), were obtained from Computerized Tomographic (CT) images of the sternum using DICOM Viewer, accurate to 0.1 cm. Subsequently, sternal area (SA) and sternal index (SI) were calculated. Univariable and stepwise multivariable discriminant function analysis (DFA) and logistic regression (LR) models were developed using a training sample (70 %), and cross-validation was performed on a holdout sample (30 %). Results showed that the linear measurements, excluding M, and sternal area were higher in males than females (P<0.001), while the sternal index was <50 % in males but >50 % in females (P<0.001). Univariable sex estimation accuracies, in cross-validation, ranged from 43.7 % to 92.9 % in DFA and 50.0–92.9 % in LR. For multivariable models, the accuracy ranges were 92.9–94.3 % in DFA and 91.6–93.0 % in LR. The sternal body length was the most accurate at 90.1 % in DFA and 90.2 % in LR, with lower sex bias (male-female) in LR than in DFA (-0.1 vs. 8.7). The sternum proves valuable for sex estimation, with sternal body length as the most accurate linear measurement. However, multivariable models, particularly LR, demonstrate higher accuracy compared to DFA.

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.

One of the most striking attacks on a commercial passenger airliner was the bombing of Pan Am Flight 103 (PA103) on 21 December 1988. Shortly after departure, the Boeing 747 “Clipper Maid of the Seas” broke apart over the Scottish town of Lockerbie. All 259 passengers and crew were killed, along with 11 residents of Lockerbie. The bombing of flight PA103 is still subject to controversy. The origin of a crucial piece of evidence, a fragment of circuit board, is highly questioned. One of the reasons for this ongoing controversy is probably that circumstantial evidence, that led to the conviction of a Libyan, is not supported by other evidence. Almost nothing is published in the forensic literature regarding the survivability of components that make up an improvised explosive device (IED). To gain insight into the survivability of IED components, suitcases, their contents, and luggage containers, a series of controlled experiments were carried out in which suitcase bombs, positioned in different configurations in aluminium LD3 luggage containers, were detonated. From the results, it could be seen that the major part of the suitcases, their contents and the LD3 containers survived the explosion. Also, almost all components of the IED itself survived the explosion to a greater or lesser extent.

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.