Institute of Environmental Science and Research Limited, Christchurch, New Zealand.
Int J Legal Med. 2011 Sep;125(5):617-28. doi: 10.1007/s00414-010-0462-4. Epub 2010 May 12.
Injuries caused by gunshots can produce what bloodstain pattern analysts know as "backspatter." Observations about the presence or absence of backspatter on an individual may be used in court as evidence of guilt or innocence. The discharge of three firearms (.22 caliber revolver, .38 caliber revolver, and .308 caliber rifle) and the resulting impact of bullets on a blood source were recorded using high-speed digital video imaging. Blood droplets, firearm muzzle gases, and ballistic shock waves were visualized using standard reflected light and shadowgraphy imaging techniques. A significant interaction between air currents, muzzle gases, and particulate material emanating from the firearms upon discharge with backspattered blood was observed. Blood droplets, initially spattered back toward the firearm and the shooter, were observed to change direction under the influence of firearm-induced air currents and were blown forward toward and beyond their original source location. Implications for experts testifying in court and for bloodstain pattern instructors are discussed.
枪击伤可产生血痕形态分析人员所知的“弹回血溅”。个体上是否存在弹回血溅的观察结果可能在法庭上被用作有罪或无罪的证据。使用高速数字视频成像记录了三把枪支（.22 口径左轮手枪、.38 口径左轮手枪和.308 口径步枪）的发射以及子弹对血液源的影响。使用标准反射光和阴影摄影成像技术观察到血滴、枪支枪口气体和弹道冲击波。在枪支发射时，空气流、枪口气体和从枪支中散发出来的颗粒物与弹回血溅之间存在显著的相互作用。最初向枪支和射手方向弹回的血滴在枪支产生的空气流的影响下改变了方向，并被向前吹向并超出其原始来源位置。讨论了对在法庭上作证的专家和血迹形态教官的影响。
