CRIME SCENE INVESTIGATIONS: GUNSHOT RESIDUE ANALYSIS ON A SINGLE GUNPOWDER PARTICLE

The article initiated a new breakthrough in identifying the presence of a gunshot residue (GSR) in crime scene investigations. According to scientists in Texas it required only a single speck of GSR smaller than a period to boost the accuracy of one of the most widely used tests integrated at crime scenes involving gunplay. This discovery seemed to be a highly dependable, rapid and inexpensive new method.

This new procedure was presented in a poster at the 235th national meeting of the American Chemical Society by Garrett Lee Burleson, a graduate student in the Master of Science in Forensic Science Program at Sam Houston State University and his advisor, a chemist Jorn Chi Chung Yu, Ph.D. of the same Sam Houston State University in Huntsville. The research was also funded by the Department of Chemistry of this school as well as the College of Criminal Justice.

The method’s highlights could be read in the original article. According to Burleson, the main focus of their research was to develop a method that would help gunshot residue credible enough to be made evidence in court. He added that results were guaranteed in thirty to forty minutes. The original article, cited that several of the current methods were vulnerable to outside interferences. Burleson added that since lead was required in most tests to make a valid reading, results were also likely to vary. And since, lead poses environmental hazards at outdoor firing ranges where it is possible to leach into groundwater, manufacturers created safer, environmentally friendly ammunition out of other metals.

This breakthrough is toward a lead-free ammunition. Burleson has cited a lot of advantages this could give compared to the traditional methods in the original article. He has used a technology called solid phase microextraction combined with gas chromatography which focused on chemical compounds present in the ejected material. According to him, no matter how small a residue particle is, it would still contain signatures of every element in that powder. He added by stating the disadvantages of the traditional method which would often fail because of lack of specificity. Analysis based on the detection of nitrites could lead to possible ambiguity in testing. This was so because, according to him, nitrites are gunpowder byproducts and could be found elsewhere.

In addition, Burleson said, that traditional methods making readings false positive, could lead to possible incarceration of an innocent person. The article ended with Burleson’s test as being excellent, reliable and cheap. However, Burleson said that for the sake of clarity and thoroughness, examiners should run multiple tests, such as the sodium rhodizonate test at the crime scene and they could then confirm the findings with his method.

Also, there are other researches, which make use of compound monocular microscopes to examine substances found at a crime scene to often establish the presence of the suspect at the scene. Compound monocular microscopes have played important roles in the study of forensic science. Expert testimony given by a specialist who has been recognized by the court as having expert knowledge about evidence in the case would find compound monocular microscopes very helpful. Original article can be found here Original article can be found here