Institute of Forensic Medicine, University of Bonn, Stiftsplatz 12, 53111 Bonn, Germany.
Forensic Sci Int Genet. 2013 Jan;7(1):22-7. doi: 10.1016/j.fsigen.2012.05.008. Epub 2012 Jun 7.
In the majority of cases suicidal shots are put to the head. Typically the gun's muzzle is held against the head. The aim of the present prospective study was to investigate whether victim DNA could reliably be recovered from the inside of the barrels of firearms that were used in 20 cases of homicidal or suicidal close contact shots. Additionally, it was investigated whether such biological traces were eliminated by subsequent firing. After autopsy sterile swabs were used to collect samples from the anterior part of the barrel thereby avoiding the muzzle. In some cases prior endoscopic inspection had revealed traces of blood and soft tissue in the barrel. For 16 cases, another swab was used to also collect sample from the posterior part of the barrel entering from its rear end. Then one shot was fired through the weapon using the same ammunition as in the suicidal shot and the sampling procedure was repeated. DNA was extracted using a magnetic beads based protocol, quantified, and STR-systems were amplified using several commercially available multiplex-STR-PCR-kits. For samples taken after the first shot DNA-analysis yielded STR profiles eligible for reliable individualization in 17 of 20 cases. After a second shot had been fired 8 or more STR systems were amplified successfully in 14 of 20 barrels.
在大多数情况下，自杀式枪击都是头部中弹。通常，枪口抵住头部。本前瞻性研究的目的是调查在 20 起凶杀或自杀近距离接触枪击案中，从用于枪击的枪支枪管内部是否可以可靠地提取到受害者的 DNA。此外，还研究了这些生物痕迹是否会被随后的射击所消除。尸检后，使用无菌拭子从前部收集枪管样本，从而避免接触枪口。在某些情况下，之前的内镜检查已经发现枪管内有血迹和软组织的痕迹。对于 16 个案例，还使用另一个拭子从后端进入枪管的后部收集样本。然后，使用与自杀式枪击相同的弹药通过武器进行一次射击，并重复采样程序。使用基于磁珠的方案提取 DNA，定量，并使用几种市售的多重 STR-PCR 试剂盒扩增 STR 系统。对于第一次射击后的样本，DNA 分析在 20 个案例中的 17 个案例中产生了可用于可靠个体识别的 STR 图谱。在进行第二次射击后，在 20 个枪管中的 14 个中成功扩增了 8 个或更多 STR 系统。
