Studies in forensic microbiology have examined the thanatomicrobiome as a new technique for determining the postmortem interval. This study focuses on the impact of various kind of soil, and water on internal organs of body after death as the bodies can be found buried under soil, and in water. Thus, this study was performed to characterise the thanatomicrobiome signatures of victim’s internal organs, such as the liver and kidney, in cadavers. Autolysis and putrefaction are two postmortem processes that are impacted by a variety of variables, including soil characteristics, microbial activity and humidity. Determining the microbial succession in water and soil at various intervals of time and at various temperatures was the aim of this investigation. The outcomes of the soil analysis and the decomposition were found to be in agreement. The current study concluded that location of the crime scene can also be determined using the post mortem interval and a thorough knowledge of decomposition procedure with respect to the microbes growing on cadaver. PMI estimation can also be enhanced by studying microbial succession based postmortem submersion interval (PMSI) considering the importance of soil and water quality. Future models of bacterial communities associated with postmortem microbial assemblage in internal organs can be created using this impact.