Potassium Cyanide and the Effect on the Rate of Decomposition of Mice in Grave-Soil

Abstract

As a body decomposes, a multitude of physiochemical changes occur that are interdependent on physical factors including temperature, humidity and pH, and victim characteristics such as weight, clothing and ante-mortem pathology. One aspect that has not been investigated is to what extent poisons such as cyanides have on a decomposing cadaver. Cyanides are used extensively throughout industry from mining to electroplating, and found in some fruits. They have also been used to commit murders and suicides. Therefore, it is necessary to determine whether cyanide has any effect on the rate of decomposition of a body buried in a soil environment as well as to assess whether overall mass loss is a viable post-mortem interval estimation method. One hundred dead house mice (Mus. musculus) were weighed and then intragastrically injected with doses of 0, 5000, 10000, 20000 and 30000 parts per million (ppm) potassium cyanide solution. The mice were then buried in separate containers of 300g top soil. Five M. musculus samples were randomly assigned to one of four Day Removal Categories (DRCs). The removal categories were 7,14,21 and 30 days after initial burial. In each DRC, the mice were removed, cleaned, photographed, characterised using a scoring system developed by Megyesi et al. [1] and then weighed again. A percentage change was calculated between the initial and removal masses. Statistical analysis was conducted using Levene Test, oneway ANOVA and Welch F-Test. Results suggested that potassium cyanide concentration was not statistically significant to the overall rate of decomposition observed, however photographs and decompositional scoring suggested there was a localised effect observed by an increased concavity of the stomach and abdominal areas. Critical analysis deemed mass loss an unviable post-mortem interval estimation tool due to a dependence on numerous factors, many of which are lost at the time of death.