Assessment of hair lesions due to sharp force wounds and entomological activity: an experimental study

The analysis of hair may provide useful information for the correct evaluation of forensic cases. In detail hair may be affected by lesions which may be caused by traumatic causes or insects: however, finding signs of sharp force weapons on hair may provide important information for the reconstruction of the manner of death, or may suggest feticist practise. This study stems from a real judicial cases where hair lesions were supposed by the defense to be due to entomological activity. In order to highlight differences between sharp force lesions and insect activity, two different experiments were performed: hair underwent several lesions by blunt and sharp force trauma in order to verify the morphology of lesions in comparison with those produced by two species of insects (Tineola Bisselliella Lepidoptera, Tineiadae and Anthrenus sp. Coleoptera, Dermestida). Hair were examined from a macroscopical and microscopical point of view by using stereomicroscopy and scanning electron microscopy. Results show that sharp force trauma produces lesions with sharp and regular edges, whereas insects leave concave lesions referable to the gnawing activity. The study highlights that insect activity leaves very specific signs and provides a hint for the correct evaluation of lesions on hair which may be found in forensic cases.