Predicting post mortem interval of hanged and surface carrions in a Nigerian Savannah: A comparative study

Abstract

This study analyzed the differences in the decomposition patterns and post mortem intervals of hanged and surface carcasses using domestic pigs as human analogs. Six domestic pigs weighing between 25 kg and 30 kg were separated into two groups comprising three pigs each. Three pigs were hanged on the branches of trees at the research facility; whereas the other three pigs were placed on the soil surface. Daily periodic decomposition observations were noted and scored for a period of 30 days alongside the accumulated degree days. There is a statistically significant (P = 0.001) difference in the decomposition between hanged and surface pigs. The hanged pigs decomposed faster at the initial stage reaching a total body score (TBS) of 10 by the second day but gradually slowed down and mummified; whereas the surface pigs initially decomposed at a slower rate but later sped up at about 167 ADD till complete skeletonization. ADD and TBS are very reliable and accurate predictors for PMI estimation of surface and hanged pig carcasses. Insect colonization of a carcass is a very important factor that determines the rate of decomposition of hanged and surface pig carcasses in Okuku, Nigeria. There is a statistically significant difference in the decomposition rate and pattern of hanged and surface pig carcasses. The prediction models for estimating PMI considered ADD and TBS as variables, and these prediction models are very reliable at 95 % confidence level.