Simulation and Observation of Vertical Cast-off Bloodstain Pattern / 法医学杂志

ABSTRACT

Objective To observe the characteristics of vertical cast-off bloodstain pattern by different hitting-tools. Methods The regular hitting tools, a kitchen knife, a dirk, a plane set-hammer and an iron pipe, were selected. At a distance of 30 cmaway fromthe wall, the hitting tool with 5 mL fresh chick-en blood made the cast-off bloodstain fromtop to bottom. Then the holistic distribution characteristics ( length , width and density ) of cast-off bloodstain and morphology characteristics ( length , width and contact angle) of first single cast-off bloodstain were analyzed. Results The distribution length of cast-off bloodstain formed by dirk was minimum( P<0 .05 ) . The distribution width of cast-off bloodstain formed by kitchen knife was minimum(P<0.05). Except the pair of kitchen knife and plane set-hammer, the distribution density between each two tools had statistical differences (P<0.05). The length of first single cast-off bloodstain formed by plane set-hammer was longest compared (P<0.05). The width of first single cast-off bloodstain had statistical differences between kitchen knife and plane set-hammer, and between dirk and plane set-hammer (P<0.05). Conclusion The type of hitting tool could be inferred by the specific characteristics of cast-off bloodstain pattern formed by every specific type of hitting tool in crime scene.