United States Bureau of Alcohol, Tobacco, Firearms, and Explosives, National Laboratory Center, 6000 Ammendale Road, Beltsville, MD, 20705, United States.
United States Bureau of Alcohol, Tobacco, Firearms, and Explosives, National Laboratory Center, 6000 Ammendale Road, Beltsville, MD, 20705, United States.
Forensic Sci Int Genet. 2020 May;46:102238. doi: 10.1016/j.fsigen.2020.102238. Epub 2020 Jan 18.
Improvements to the DNA analysis of fired cartridge cases have been made in recent years, yet successful analysis of this important evidence type remains difficult. In this study, we describe both a novel device for the collection and transport of fired cartridge cases and a new DNA recovery method that incorporates a rinse-and-swab technique. This technique combines two different types of swabs and a rinse solution with additives that reduce the degradative effects that copper has on DNA. The new recovery method yielded approximately threefold more DNA than the traditional double swab method and reduced the evidence of degradation. After validation, we estimated the real-world success rate of obtaining DNA profiles suitable for comparison with the rinse-and-swab method by testing over 100 cartridge cases collected from crime scenes. Approximately 67 % of the time (8 of 12), at least one DNA profile suitable for comparison was obtained from fired cartridge cases assumed to be associated with a single firearm using the collection device and the rinse-and-swab method when the fired cartridge cases were collected within 24 h.
近年来，对射击过的弹壳的 DNA 分析有了改进，但成功分析这种重要证据类型仍然很困难。在这项研究中，我们描述了一种用于收集和运输射击过的弹壳的新型装置以及一种新的 DNA 回收方法，该方法结合了冲洗和擦拭技术。该技术结合了两种不同类型的拭子和一种含有添加剂的冲洗溶液，可减少铜对 DNA 的降解作用。与传统的双拭子法相比，新的回收方法可多提取约三倍的 DNA，并减少了降解证据。经过验证，我们通过测试从犯罪现场收集的 100 多个弹壳，估计了使用收集装置和冲洗擦拭法从假定与单个枪支有关的射击过的弹壳中获得适合与冲洗擦拭法进行比较的 DNA 图谱的实际成功率。当在 24 小时内收集射击过的弹壳时，使用收集装置和冲洗擦拭法，大约有 67%的时间（8 次中有 1 次）至少可以从射击过的弹壳中获得一个适合与冲洗擦拭法进行比较的 DNA 图谱。
