With the development of technology, the gun can be attributed as one of the deadliest weapons that has been developed. However, guns have been used in killing people, necessitating the development of the technology commonly used in forensics which is Gunshot residue (GSR), also known as cartridge discharge. The GSR is a piece of significant trace evidence that has been used to identify the shooters in firearm-related incidences. The exercise detects traces of GSR in suspects’ clothes with this technology dating years back. This residue contains three primary elements: lead, barium, and antimony (Girard, 2017, p. 214). To understand the GSR concept, one has to know the sampling and analyzing process.
Before collecting these samples from the subjects, it is crucial to take some caution when firearm discharge incidences are reported. The first caution is when the sample has to be collected as early as possible to avoid particle loss due to daily activities. Secondly, the collector must ensure no or less contamination to preserve the quality and integrity of the evidence leading to a forensics report. Lastly, the possible sources of the primary elements in the GSR should be considered, such as the occupation of the subjects or the possibility of the subject being near to early firearm discharge. After taking all the considerations above, the hands of the victim and suspected shooter are swapped with 5% nitric acid solution, and the sample is collected on a Scanning electron microscope (SEM) collection disk (Girard, 2017, p. 221). The collected sample is then forwarded to the laboratory for analysis.
The GSR analysis is done using a scanning electron microscope. The microscope allows the scientists to identify the three elements through their shape and chemical makeup. Upon analysis, evidence is sealed; however, the evidence doesn’t need to be accepted. In other cases, the analysis report is made of a brief synopsis of the case. The investigators should always avoid contamination of the evidence to improve the integrity of the report.
Reference
Girard, J. E. (2017). Criminalistics. Jones & Bartlett Learning.