The "body farm" in the Ticino Park - botanical evidence on skin and hair

Environmental traces can be a valuable resource for identifying places, times and subjects involved in a criminal event. However, the routine sampling of the cadaver in search of these traces is still not very widespread. For this reason, the awareness of the research of this kind of traces, in particular of botanica ones, must increase amongst representatives of the Forensic Scientific Community as well as the potential and limits of the differents human substrate. A series of 8 samples, consisting of one piglet and 10 locks of hair, have been placed in a large natural park, the Ticino Park: 6 in a wooded area and 2 in a grassland. The latter were moved to the wooded area after 3 days. All the samples stayed in the environment for over 8 months. During this interval 10 samplings were carried out through a survey of the surrounding vegetation and of the corpses in terms of body preservation and environmental contaminants (especially botanical). Environmental footprint increasingly marks the samples starting from 48 hours after placement, the grassy environment is no longer identifiable after 11 days post movement in woodland, botanical evidence allows a sub-seasonal and intra-environment characterization of pigs. Skin proves to be poorly persistent; it disappears between 15 days and 1 month; however, certain areas undergo conservative processes thanks to the local environmental conditions. The accumulation trend of botanical elements on skin is interrupted with the disappearance of the substrate and restarts on the underlying one (bones). Skin retains all types of botanical traces. On hair locks, on the contrary, the accumulation trend is not interrupted due to the great preservability of the substrate; however, it is a selective substrate that retains only specific types of botanical elements. As outlined, forensic botany can provide information that, even if only circumstantial, can certainly shed light on many of the classic queries that judicial investigators advance. However, this information requires a careful analysis and sampling of all available substrates. Having highlighted the different characteristics of persistence and selectivity of skin and hair, it is clear that only their combined exploitation can allow the collection of the complete pool of information.