Post-mortem interval

Changes to a body occurring after death (post-mortem changes) include: Factors that can affect the rate of human decomposition are concerned with the particular environment a body has been recovered from. A very approximate rule of thumb for estimating the postmortem interval is as follows: • Warm and flaccid: less than 3 hours • Warm and stiff: 3 to 8 hours • Cold and stiff: 8 to 36 hours • Cold and flaccid: More than 36 hours. Due to significant environmental variations between regions, universal formulas would be ill-suited for this topic in forensic science. ==Analytical techniques==

There are analytical techniques that can be used to determine the post-mortem interval: • Ocular changes: vitreous chemistry composition, eye structural changes. • State or stage of decomposition: autolysis (process of self-digestion) and putrefaction (process caused by bacteria found within the body). More advanced methods include DNA quantification, infrared spectroscopy, and for buried individuals changes in soil composition such as the levels of methane, phosphates and nitrates, ninhydrin-reactive nitrogen, volatile organic compounds, and water conductivity, could also reveal the time of death. ==References==