TY - JOUR PY - 2012// TI - Raman Spectroscopic Analysis of Gunshot Residue Offers Great Potential for Caliber Differentiation JO - Analytical chemistry A1 - Bueno, Justin A1 - Sikirzhytski, Vitali A1 - Lednev, Igor K. SP - 4334 EP - 4339 VL - 84 IS - 10 N2 - 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 9mm 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.

Language: en

LA - en SN - 0003-2700 UR - http://dx.doi.org/10.1021/ac203429x ID - ref1 ER -