Identification case report of gunshot residues deposited on a vehicle window subjected to multiple shots at close range

Abstract

 The multiple shots from the close range to a vehicle had occurred, and seven entrance holes was observed on the side window of the vehicle. After the analysis of the residues collected around the holes, the part of the residues had included the specific elements: lead, barium, and antimony. Based on the analysis results, the residues were concluded as GSR. However, the collected samples had included few numbers of the particle consisted of the specific three components comparing to the one or two components. So, we arranged the firing experiment to clarify the reason why the less amount of three components particles was detected.

 The experimental results showed that the total amount of lead-containing particles had increased and the ratio of three components particles had decreased, with the shooting distance getting close.

 In this paper, we suggested the two points below for the identification of GSR collected from the target subjected to a close-range shot.

(1) Analyze as many particles as possible using the automatic analysis function so as not to miss the three components particles.

(2) Focus on not only the three components particles but also particles containing the one or two specific elements to improve the reliability of the positive results.