Soil mites as forensic markers of decomposition of corpses and carcasses

The use of forensic entomology in providing reliable death-time estimates using knowledge of carrion insect species’ ecology and larval development has been used for many years. Aside from insects, mites (Acari) can act as reliable indicators of time of death. The use of forensic acarology is growing rapidly into a valuable additional input into forensic analysis. This field of forensic analysis has always been closely connected to forensic entomology. This study aimed to identify and qualitatively assess the mites of forensic importance within the outdoor environment. The outcomes from this study provide data that will enable a basic forensic acarology service to be provided in other research, as well as initiate further development of forensic acarology in crime scene investigations. The ubiquitous of mites in the soil beneath corpses adding valuable information on decomposition process and reconstruct the scene of death. Using the micro-habitat specific to mites, the abundance, species richness and composition of mite orders was examined and compared and the unique presence of certain mites would be uncovered. Two outdoor settings for forensic study were set up by using pigs as proxies for human cadavers: 1) seasonal study of temperate area with four different seasons in almost 2 years (November of 2013 – August 2015) 2) carcass position/condition over a year (Jun 2013 – September 2014). The majority of mites found were phoretic with the mesostigmatid families, Macrochelidae and Parasitidae the most abundant. There are few quantitative data available on the carcass colonisation patterns of insects and other arthropods; however these data are forensically valuable. There may be differences in the taxa collected during this successional study on pigs and those that occur on human bodies from different habitats. Therefore, mites collected from three crime cases were used to prove the reliable approaches in using pig carcasses to the real cases. The mites present on the corpses were compared with those collected from the pig carcasses and there was extremely close agreement between the mite presence from bodies and carcasses