Estimation of Postmortem Interval in Human Cadavers Using Two Different Quantitative Methodologies

Postmortem interval (PMI) is defined as the time between death and discovery of the deceased. It is important in criminal investigations because it allows investigators to draw conclusions about the circumstances surrounding the death of a person. The postmortem interval is estimated using many different methods. Currently, the standard of the field is the use of insect succession or physiological age of insect larvae to determine PMI; however, quantitative scoring methodologies have become more common as they aim to allow non-professionals to efficiently estimate PMI in the field. Two quantitative methods of estimating PMI are Vass’ universal PMI formula and Megyesi's total body scoring (TBS) system. However, the validity of these methods across different regions is unknown. We found that actual PMI and PMI estimated using Vass’ universal formula were statistically different from one another (p < 0.001). There was not enough evidence to show that actual PMI and the TBS calculated PMI were statistically different from one another (p = 0.208). We know that decomposition is highly variable and dependent upon region/climate. From this, we can conclude that Vass’ ‘universal’ PMI formula is not a reliable method of estimating PMI in Southeast Texas.