Decomposition is degradation process of a corpse into basic respective constituents macroscopically and microscopically by action of microorganisms, arthropods and scavengers. Post mortem changes could be separated into early post mortem changes (i.e. algor mortis, rigor mortis and livor mortis) and putrefaction stages of corpse. These changes function as suitable indicators for determination of post mortem interval (PMI). In this paper, different stages of post mortem changes, possible variations such as mummification and formation of adipocere and special circumstances such as burial condition is discussed. This article also refers to several arguments in the different texture of adipocere and the influence of different types of fabric in affecting the post mortem changes and formation of adipocere. This is largely due to the property of permeability and resistance of material against degradation process. Undeniably, decomposition process involves numerous potential variables including burial condition, presence of clothing, potential formation of adipocere and mummification. Hence, studies in forensic taphonomy combined with real case scenario are crucial in understanding the nature of decomposition and estimation of PMI with higher accuracy.
Establishing time of death has been extensively studied for the last 30 years. Parameters that have been studied included body temperature, biochemistry of rigor mortis, putrefactive changes and entomology. Despite an extensive study in these parameters it was found that all of the parameters were very much dependent on external factors like changes in surrounding temperature and activities done prior to death. To solve this problem, we decided to monitor the mechanism that occurs during death. Until now, various researches have found that during the early stage of death, heart and perfusion to the cells will stop. This will cause the cells to start the death process. The death of the cell will occurs either through apoptosis or necrosis. During apoptosis the cells will switch on and off a few proteins in a sequence. Based on this understanding, a study was conducted to determine if area ratio of apoptosis: necrosis and apoptotic p53 and Bcl-2 markers can be used as a reliable postmortem interval marker (PMI). Sampling of the study had involved 100 dead human skins with a known PMI. All samples were obtained from forensic unit of Hospital Kuala Lumpur (UFHKL). Ratio of apoptosis: necrosis areas were determined using hematoxilin and eosin staining while apoptosis p53 and Bcl-2 markers were done using an apoptosis kit. All staining were then indexed and plotted against PMI data obtained from UFHKL. Results indicated that there were no significant correlations between ratio of apoptosis: necrosis area against PMI (p = 0.144). Whereas for both apoptotic markers p53 and Bcl-2 PMI had shown a significant correlation (p < 0.000 for both results). In conclusion, we suggest that p53 and Bcl-2 parameters should be studied further since it is very likely that it could be a good indicator for PMI.