Scanning Electron Microscopy and X-Ray Microanalysis for Chemical and Morphological Characterisation of the Inorganic Component of Gunshot Residue: Selected Problems

Abstract

Chosen aspects of examinations of inorganic gunshot particles by means of scanning electron microscopy and energy dispersive X-ray spectrometry technique are presented. The research methodology of particles was worked out, which included a precise and repeatable procedure of the automatic detection and identification of particles as well as the representation of the obtained analytical data in the form of the frequencies of occurrence of particles of certain chemical or morphological class within the whole population of particles revealed in a specimen. On this basis, there were established relationships between the chemical and morphological properties of populations of particles and factors, such as the type of ammunition, the distance from the gun muzzle to the target, the type of a substrate the particles sediment on, and the time between shooting and collecting the specimens. Each of these aspects of examinations of particles revealed a great potential of being utilised in casework, while establishing various circumstances of shooting incidents leads to the reconstruction of the course of the studied incident.

Chemical and physical characterisation of welding fume particles for distinguishing from gunshot residue

“…Each chemical class of particles was defined by setting the list of contributing elements, within broad ranges of their composition, typically between 0 and 100%. The measurement setting was selected so that particles of 0.9 mm in diameter would not be missed (Table 2), as it has been established that the prevailing fraction of GSR particles is that of about 1 mm size [3,[12][13][14].…”

“…That makes them distinguishable from other anthropogenic particulate matter by means of the scanning electron microscopy coupled with the energy dispersive X-ray spectrometry (SEM-EDX) [3]. The analytical approach based on SEM-EDX gained widespread success in various fields of science, mainly because the technique simultaneously provides the information on the elemental contents and morphological features of the materials of interest, and may focus on fine objects, e.g.…”

The fate and behaviour of gunshot residue: recreational shooter distribution

“…Several studies have highlighted the ease with which GSR particles can be transferred to a variety of surfaces by surface contact, rubbing and particle sedimentation (5,17,63,69,80). Problems associated with secondary transfer of GSR have been noted during arrest and during police transit.…”

Detection of Pb, Ba, and Sb in Blowfly Larvae of Porcine Tissue Contaminated with Gunshot Residue by ICP OES

“…In this context, the use of analytical techniques in forensic analysis to GSR identification is becoming increasingly important in the replacement of traditional qualitative methods as colorimetric assays [7][8][9][10][11][12]. The inductively coupled plasma-optical emission spectrometry technique (ICP OES) [13,14] becomes promising in this sense because it has good sensitivity in the analysis of metals in addition to being multielement, simple, quick, and cheap when compared with other techniques such as scanning electron microscopy with X-ray energy dispersive detector (MEV/EDX) [12,[15][16][17] and inductively coupled plasma mass spectrometry (ICP-MS) [18][19][20].…”