Raman Spectroscopic Analysis of Gunshot Residue Offering Great Potential for Caliber Differentiation
Raman Spectroscopic Analysis of Gunshot Residue Offering Great Potential for Caliber Differentiation
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DOI：
10.1021/ac203429x
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发表时间：
2012-05-15
影响因子：
7.4
通讯作者：
Lednev, Igor K.
中科院分区：
文献类型：
--
作者：
Bueno, Justin;Sikirzhytski, Vitali;Lednev, Igor K.
利用近红外(NIR)拉曼光谱结合先进统计技术，对来自不同口径弹药的枪击残留物(GSR)微粒进行了区分。枪械发射过程类似于复杂的化学反应。这一过程的试剂由弹药、枪支和弹壳的化学成分表示。具体的枪械参数决定了反应的条件，从而决定了后续产品的GSR。我们发现，从这些产品收集的拉曼光谱对于不同口径的弹药是有特征的。以9 mm和0.38口径弹药在相同放电条件下采集的火药颗粒为例，验证了共焦拉曼光谱技术对火药颗粒的分辨和识别能力。该算法基于支持向量机和偏最小二乘判别分析，采用留一交叉验证法进行验证。这项研究首次证明了近红外拉曼显微光谱具有基于取证相关参数(如口径大小)的无试剂区分GSR的潜力。当这种方法得到充分发展后，应该会对犯罪现场调查的效率产生重大影响。
Near-infrared (NIR) Raman microspectroscopy combined with advanced statistics was used to differentiate gunshot residue (GSR) particles originating from different caliber ammunition. The firearm discharge process is analogous to a complex chemical reaction. The reagents of this process are represented by the chemical composition of the ammunition, firearm, and cartridge case. The specific firearm parameters determine the conditions of the reaction and thus the subsequent product, GSR We found that Raman spectra collected from these products are characteristic for different caliber ammunition. GSR particles from 9 mm and 0.38 caliber ammunition, collected under identical discharge conditions, were used to demonstrate the capability of confocal Raman microspectroscopy for the discrimination and identification of GSR particles. The caliber differentiation algorithm is based on support vector machines (SVM) and partial least squares (PLS) discriminant analyses, validated by a leave-one-out cross-validation method. This study demonstrates for the first time that NIR Raman microspectroscopy has the potential for the reagentless differentiation of GSR based upon forensically relevant parameters, such as caliber size. When fully developed, this method should have a significant impact on the efficiency of crime scene investigations.