13th International Conference on Fracture June 16–21, 2013, Beijing, China -9- simulated the backspatter particle speed, timing and spray pattern consistent with the same experiment. Finally from the materials we tested, MDF was found to be best suited to simulating skull/bone. MDF is a better simulant material for skull than polycarbonate under high velocity projectile impact. MDF displays similar brittle properties to bone and produced backspatter. Polycarbonate was very ductile with limited material fracture thus was not a good simulant for bone. Future work will focus on extending the model to multiple layers and ductile materials. This can be extended to include biological material with an anatomically based human or porcine model. Other mechanisms such as intracranial overpressure and the subcutaneous gas effect have also been theorised. A computational model could be further extended to simulate these mechanisms of backspatter. This would create a more complete model of what happens in reality. This research is thus an important step towards creating a tool to help forensic scientists accurately recreate crime scenes and provide evidence that leads to justice in serious crime investigations. References [1] R.M. Coupland, M.A. Rothschild, M.J. Thali, B.P. Kneubuehl, R.M. Coupland, M.A. Rothschild, and M.J. Thali, Introduction to Wound Ballistics. ed. B.P. Kneubuehl: Springer Berlin Heidelberg 2011, pp. 1-2. [2] B.G. Stephens, and T.B. Allen, Back Spatter of Blood from Gunshot Wounds - Observations and Experimental Simulation. Journal of Forensic Sciences, vol. 28 (2) (1983). pp. 437-439. [3] B. Karger, R. Nusse, and T. Bajanowski, Backspatter on the Firearm and Hand in Experimental Close-Range Gunshots to the Head. The American Journal of Forensic Medicine and Pathology, vol. 23 (3) (2002). pp. 211-213. [4] J.O. Pex, and C.H. Vaughan, Observations of High Velocity Bloodspatter on Adjacent Objects. Journal of Forensic Sciences, vol. 32 (6) (1987). pp. 1587-1594. [5] K. Yen, M.J. Thali, B.P. Kneubuehl, O. Peschel, U. Zollinger, and R. Dirnhofer, Blood-Spatter Patterns: Hands Hold Clues for the Forensic Reconstruction of the Sequence of Events. American Journal of Forensic Medicine and Pathology, vol. 24 (2) (2003). pp. 132-140. [6] B. Karger, R. Nusse, H.D. Troger, and B. Brinkmann, Backspatter from Experimental Close-Range Shots to the Head II- Microbackspatter and the Morphology of Bloodstains. International Journal of Legal Medicine, vol. 110 (1997). pp. 27-30. [7] M.A. Verhoff, and B. Karger, Atypical gunshot entrance wound and extensive backspatter. Int J. Legal Med., vol. 117 (2003). pp. 229-231. [8] M. Kleiber, D. Stiller, and P. Wiegand, Assessment of shooting distance on the basis of bloodstain analysis and histological examinations. Forensic Science International, vol. 119 (2001). pp. 260-262. [9] B. Karger, R. Nusse, G. Schroeder, S. Wustenbecker, and B. Brinkmann, Backspatter from Experimental Close-Range Shots to the Head I-Macrobackspatter. International Journal of Legal Medicine, vol. 109 (1996). pp. 66-74. [10]M.J. Thali, K. Yen, P. Vock, C. Ozdoba, B.P. Kneubuehl, M. Sonnenschein, and R. Dirnhofer, Image-guided virtual autopsy findings of gunshot victims performed with multi-slice computed tomography and magnetic resonance imaging and subsequent correlation between radiology and autopsy findings. Forensic Sci Int, vol. 138 (1-3) (2003). pp. 8-16. [11] S.A. Padosch, R.B. Dettmeyer, C.W. Schyma, P.H. Schmidt, and B. Madea, Two simultaneous suicidal gunshots to the head with robbed police guns. Forensic Science International, vol. 158 (2-3) (2006). pp. 224-228. [12]M.C. Taylor, T.L. Laber, B.P. Epstein, D.S. Zamzow, and D.P. Baldwin, The effect of firearm muzzle gases on the backspatter of blood. International Journal of Legal Medicine, vol. (2010). pp. 1-12.
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