• Biomedical Science Letters
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• v.24 no.1
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• pp.35-42
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• 2018

Postmortem interval (PMI) is very important in the crime scene investigation. However, it is very difficult to estimate of the interval since death after a decomposition. Recently, there have been various studies on the postmortem interval since a decomposition. In particular, the total body score (TBS) and accumulated degree days (ADD) used to estimate the postmortem interval after a decomposition. This study was conducted with the aim of applying the TBS and ADD to estimate the postmortem interval in real forensic caseworks. In first murder case, TBS was 12 and ADD value was 132, respectively. An estimated time of PMI was around 23:00 on June 21, and the suspect's statement was 01:20 on June 22. Our estimated interval since death and the suspect's statement for the PMI differ by only 2 hours and 20 minutes. In second forensic case, TBS was 3 and ADD value was 55, respectively, an estimated time of PMI was around 02:26 on September 23. The suspect's statement was 10:30 on September 23. Our estimated time and the suspect's statement for the PMI differ by 8 hours. In these cases, we were able to have confirmed the feasibility of TBS and ADD on the real forensic cases. Overall, our finding suggested that the quantitative method could be used to produce PMI estimates that are accurate to within days or even hours.

• Molecules and Cells
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• v.40 no.6
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• pp.410-417
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• 2017

Estimation of postmortem interval (PMI) is a key issue in the field of forensic pathology. With the availability of quantitative analysis of RNA levels in postmortem tissues, several studies have assessed the postmortem degradation of constitutively expressed RNA species to estimate PMI. However, conventional RNA quantification as well as biochemical and physiological changes employed thus far have limitations related to standardization or normalization. The present study focuses on an interesting feature of the subdomains of certain RNA species, in which they are site-specifically cleaved during apoptotic cell death. We found that the D8 divergent domain of ribosomal RNA (rRNA) bearing cell death-related cleavage sites was rapidly removed during postmortem RNA degradation. In contrast to the fragile domain, the 5' terminal region of 28S rRNA was remarkably stable during the postmortem period. Importantly, the differences in the degradation rates between the two domains in mammalian 28S rRNA were highly proportional to increasing PMI with a significant linear correlation observed in mice as well as human autopsy tissues. In conclusion, we demonstrate that comparison of the degradation rates between domains of a single RNA species provides quantitative information on postmortem degradation states, which can be applied for the estimation of PMI.

• Journal of Veterinary Science
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• v.25 no.3
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• pp.24.1-24.9
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• 2024

Importance: In veterinary forensic science, accurately determining the postmortem interval (PMI) is crucial for identifying the causes of animal deaths. Autolysis, a significant postmortem process, influences PMI estimation, but its relationship with humidity is not well understood. Objective: This study aimed to improve the accuracy of PMI estimates in veterinary forensic cases by looking into how different humidity levels affect autolysis in different organs of rats. Methods: The study involved 38 male rats, examining histopathological changes in their heart, liver, and pancreas. These organs were subjected to controlled humidity levels (20%, 55%, and 80%) at a constant 22℃. Tissue samples were collected at several intervals (0 h, 12 h, 24 h, 3 days, and 8 days) for comprehensive analysis. Results: Distinct autolytic characteristics in animal organs emerged under varying humidity conditions. The low-humidity environment rapidly activated autolysis more than the high-humidity environment. In addition, it was found that lower humidity caused nuclear pyknosis, cytoplasmic disintegration, and myofiber interruption. The liver, in particular, showed portal triad aggregation and hepatocyte individuation. The pancreas experienced cell fragmentation and an enlarged intracellular space. High humidity also caused the loss of striations in cardiac tissues, and the liver showed vacuolation. Under these conditions, the pancreas changed eosinophilic secretory granules. Conclusions and Relevance: The study successfully established a clear connection between the autolytic process in PMIs and relative humidity. These findings are significant for developing a more accurate and predictable method for PMI estimation in the field of veterinary forensic science.

• The Korean Journal of Legal Medicine
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• v.42 no.4
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• pp.126-140
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• 2018

The diagnosis of cause of death (COD) or estimation of postmortem interval (PMI) is hard to perform using postmortem blood or other bodily fluids due to various biochemical changes that occur during the agonal phase or after death. To solve these problems, new paradigms and new analytical methods are needed. In this study, postmortem blood was fractionated with specific gravity 1.021, 1.029, 1.038, and 1.045, and the absorbance patterns of each sample of the 131 total cases (12 kinds of COD) were analyzed using a spectrometer. The absorbance was grouped into 9 patterns (ABS pattern 1 to 9) according to the wave length and the signal intensity. These patterns of postmortem blood were found to be distinctly different from the absorbance pattern of fresh blood. The analysis of ABS patterns is useful for the diagnosis of deaths due to acute or rapid bleeding, fire death, drowning and, in some cases, poisoning, but is not useful for the estimation of PMI.

• Journal of Science Criminal Investigation
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• v.11 no.3
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• pp.178-185
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• 2017

It is one of the most important factors to statistical estimation of ambient temperature for accumulated degree day (ADD) and minimum postmortem interval (PMI) in the incident scene. Until now, we applied the temperature of the nearest weather stations, adjusted temperature, or estimated the temperature by the linear regression analysis to estimate the temperature of the incident site. At this time, the estimated temperature may be changed according to the method of temperature estimation. And The accuracy of the estimated value may also vary depending on the environmental factors such as capacity, wind speed, humidity, and rainfall, which may affect measurement conditions and temperature. Therefore, we studied the effect of various environmental factors and measurement conditions for ambient temperature in Korea.

• Journal of Life Science
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• v.18 no.10
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• pp.1400-1409
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• 2008

This study was carried out to offer the forensic entomological evidence to estimate the postmortem interval (PMI) based on the decomposing state of the pig carrion and the arthropod succession in exposed carrion. A total of 48 species of 28 families belonging to 7 orders were collected, and dominant insect varied with season, i. e., the Calliphoridae in March, May and October, both of the Calliphoridae and the Staphylinidae in July, and the Staphylinidae in September. The Calliphoridae was the first visiting insect throughout all the seasons as well as the index insect dominant in the early decomposing stage. The index insect in the later decomposing stage, however, was the Staphylinidae throughout all the seasons except in March. In March, the Muscidae was dominant, presumably because the flies consistently arrived throughout the extended period of decomposition of the carrion owing to the low ambient temperature of the season. In this connection, it is known that not only the decomposition stage of the carrion and the carrion-associated insect but also the climatological condition of the region have to be taken into consideration to estimate the PMI.