The botanist - entomologist's best friend

Forensic entomology and botany are respectively the sciences of collecting and analysing insect and plant evidence to support forensic investigations. The entomological method is still the most reliable method for establishing the minimum time since death (Post Mortem Interval, PMI) during the first weeks post-mortem. Forensic botany however is still an under-utilized resource in forensic investigations, which may provide useful spatial and temporal information in outdoor cases. The present paper describes principles and methods applied to collect and analyse entomological and botanical evidence in four real cases which occurred in Northern Italy and compares the information obtained through both disciplines, in order to outline their potentiality, complementarity and limits. Entomological and botanical evidence were collected on the field and/or during the autopsy. The entomological evidence was discussed considering the phenology of the species and the composition of the observed insect community. Botanical evidence (plant macroremains, phenology, dendrochronology) was used to estimate the residence time of the remains and their possible previous localization. In case 1, a skull was found on a tree in a park; in this case botanical evidence (plant macroremains and moss growth) provided the main spatial and temporal frame. In case 2 a completely skeletonised body was found in a woodland; as larval activity had stopped in time, in this case also botany gave important information for PMI estimation through the analysis of spatial relationships between skeletal remains and litter deposition. In case 3, a body in a state of advanced decay was found in a ditch. In this case entomological evidence allowed for crucial and accurate estimate of PMI which was supported also by the phenology of plant individuals associated with the body . In case 4: a body was found closed in a plastic bag, wrapped in a wool blanket and buried. In this case entomology and plant remain analysis were absolutely complementary in providing a detailed PMI estimation. Our results confirm that the two methods in some situations are mutually complementary. Where both methods were applied to the examined cases, a larger amount of information could be obtained. In outdoor cases, a multidisciplinary approach could be the most reliable tool of success together with the pathologist’s or anthropologist’s standard methods such as ADD