{"title":"A forensic engineering technique for analysis of an explosion incident.","authors":"Ganchai Tanapornraweekit, Thimira Abeysinghe, Somnuk Tangtermsirikul","doi":"10.1111/1556-4029.70005","DOIUrl":"https://doi.org/10.1111/1556-4029.70005","url":null,"abstract":"<p><p>This article investigates the validity of current forensic practices to analyze an explosion event. The purpose of this study is to use forensic engineering techniques with the integrated models for the simulation of blast fragments and blast pressure to determine an explosive weight used in a bombing incident and later predict a lethal radius caused by blast pressure and a lethal zone caused by fragment impact. The real explosion incident at the Erawan shrine in central Bangkok on August 17, 2015, is selected as a case study. By comparing the structural damage at the blast site to the one obtained from finite element (FE) analyses, an estimated bare charge weight of TNT used in the incident can be obtained. It was found that an estimated bare charge of 3 kg TNT equivalent could have been used for the bomb. To confirm the validity of the calculated explosive weight, a combined lethal zone from blast pressure and scattered fragments was analyzed. Human damage due to the blast pressure is analyzed based on Bowen's lethality curves. The lethality zone from expelled fragments is drawn based on a 50% probability of lethality, which considers the hit density and kinetic energy of the fragment. The analyzed lethal zone agrees reasonably well with the actual observed human damage level. The proposed forensic engineering technique offers the potential for enhancing management and policies in homeland security, contributing to a safer community.</p>","PeriodicalId":94080,"journal":{"name":"Journal of forensic sciences","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143434738","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Stephanie M Betts, Ivette A Espinoza Quiroga, Linda M Otterstatter, Joseph Donfack
{"title":"Hair root sonication washing impact on nuclei counts.","authors":"Stephanie M Betts, Ivette A Espinoza Quiroga, Linda M Otterstatter, Joseph Donfack","doi":"10.1111/1556-4029.70002","DOIUrl":"https://doi.org/10.1111/1556-4029.70002","url":null,"abstract":"<p><p>In a previous study, hair samples were washed by sonication in Terg-a-zyme™ (Alconox, White Plaines, NY, USA) as part of the DNA extraction protocol. The sonication wash step was deemed necessary in the previous study because the DNA extracts could be used for both mitochondrial (mt) and nuclear(nu) DNA analyses. In the current study, the impact of the sonication wash on the persistence of nuclei was assessed. Scalp hair roots were stained using the DNA binding dye 4', 6-diamidino-2-phenylindole (DAPI) and visible nuclei were counted. Hair roots that contained <50 visible nuclei were primarily used to monitor the change in the number of visible nuclei due to sonication. Hair roots with a larger number of nuclei counts (e.g., >100) were also included as comparative data. The selected hair samples were washed by sonication in Terg-a-zyme™. The number of nuclei detected in unwashed DAPI-stained hair roots was compared with the number in washed DAPI-stained hair roots. Intricacies that impeded visible nuclei counting in the same hair root were observed, such as orientation of the mounted hair root, hair root morphology, turgescence, and folding of soft tissue. Despite these challenges, this study showed the sonication wash of hair roots containing <50 visible nuclei might lead to a reduction of nuclei available for DNA extraction and short tandem repeat (STR) typing. However, for laboratories performing only nuDNA analysis, the sonication could be replaced with a less aggressive hair washing method such as briefly vortexing at low speed in saline followed by an ethanol rinse.</p>","PeriodicalId":94080,"journal":{"name":"Journal of forensic sciences","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143434746","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The influence of perceived difficulty, availability of marks, and examination time on the conclusions of firearms examiners.","authors":"Keith L Monson, Erich D Smith, Eugene M Peters","doi":"10.1111/1556-4029.70004","DOIUrl":"https://doi.org/10.1111/1556-4029.70004","url":null,"abstract":"<p><p>Concurrent with studies on the accuracy, repeatability, and reproducibility of decisions based on comparisons of fired bullet and cartridge cases, we also collected the opinions of the participating examiners as to the characteristics of the specimens provided and the difficulty of making comparisons. Examiners rated the ease with which they determined every conclusion (easy, average, hard) and estimated qualitatively the amount of visual information available to them in determining a conclusion (limited, some, extensive). Comparisons deemed hard were perceived generally to have somewhat fewer markings conducive for assessment, while comparisons where the markings were limited produced a larger number of inconclusive determinations. Perceived difficulty increased with wider separation in firing order (within or between three defined segments of 700-850 total firings). The repeatability of these qualitative assessments exceeded 60% and their average reproducibility was ~50%. Examination times did not vary significantly when rendering decisions of identification, elimination, or inconclusive, although bullet identifications appear to have taken slightly longer than those for cartridge cases. Hard comparisons, where the amount of information was limited, were not treated substantially differently from any other types of comparison. No correlation was found between difficulty and number of comparisons attempted. These results tend to contradict assertions by critics that examiners are tempted to declare inconclusive decisions to save time and avoid rendering an elimination or identification conclusion, or that the results are non-representative of casework, or that perceived difficulty affected the degree of examiner participation.</p>","PeriodicalId":94080,"journal":{"name":"Journal of forensic sciences","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143416488","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Genotyping strategies for tissues fixed with various embalming fluids for human identification, databasing, and traceability.","authors":"Madeline Ashton, Natalia Czado, Michelle Harrel, Sheree Hughes","doi":"10.1111/1556-4029.15414","DOIUrl":"10.1111/1556-4029.15414","url":null,"abstract":"<p><p>Within anatomical willed body programs and skeletal collections, whole bodies and their disassociated limbs and organs are identified and tracked. However, if these tracking mechanisms fail, DNA recovered from the formalin-fixed tissues/organs could provide an additional layer of quality assurance. Embalming fluids preserve biological tissues; however, they also damage, fragment, and cross-link DNA and protein molecules. This project investigated the success of STR-typing from various soft tissue and bone samples that were fixed with embalming solutions with a range of formaldehyde concentrations. Formalin-fixed samples dissected from five cadavers, including skin, muscle, bone, heart, and kidney were used in Phase 1 of this study. In Phase 2, an additional 57 tissue samples from various embalmed organs and body parts were collected to demonstrate long-term fixation and direct applicability within a body donor program. DNA was extracted from the samples using the QIAamp® FFPE Tissue Kit (QIAGEN), quantified with the Investigator® QuantiPlex® Pro RGQ qPCR Kit (QIAGEN), and amplified using the Investigator® 24plex and 26plex QS Kits and the Investigator® DIPplex Kit (QIAGEN). The results show the DNA was severely damaged, degraded, and often in low amounts (after one year post-embalming). Sampling from skin and muscle tissues embalmed with ~2.5%-5% formaldehyde solutions appears to be the best strategy for identification, while also maintaining the preservation of the tissues. The results of this project can provide informative data when determining which genotyping strategy may be best suited for the identification, re-association, and establishment of a database for the provenance of formalin-fixed human remains.</p>","PeriodicalId":94080,"journal":{"name":"Journal of forensic sciences","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71416309","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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