Forensic investigators may soon add two new techniques for examining a gun crime, thanks to the savvy of Lamar University chemistry professors. Their research provides investigators with methods to determine the brand of ammunition used and to estimate from how far a shot was fired.
The groundbreaking research by J. Wayne Rabalais, Distinguished Professor in the Department of Chemistry and Physics at Lamar, and department colleagues Yongyan Mou, a postdoctoral associate at Lamar, and Jyoti Lakadwar, a graduate student at Lamar, has been submitted to the Journal of Forensic Science for peer review and consideration for publication. Mou's work at Lamar is supported by the R.A. Welch Foundation, which was created in 1954 to support chemical research in Texas.
In their research, atomic force microscopy and Fourier transform infrared attenuated total internal reflection techniques were applied to the analysis of gunshot residue to determine the shooting distance and cartridge type. In their paper, "Evaluation of Shooting Distance and Discrimination of Cartridge Type by the Analysis of GSR," the authors describe how they were able to correlate the shapes and sizes of gunshot residue particles with shot distance.
Analysis of the components of the gunshot residue produced distinctive bands in the infrared spectrum, allowing identification of the brand of gunpowder fired. Gunpowders are primarily composed of propellant, a plasticizer that serves as a binder, and stabilizers that forestall chemical deterioration. Manufactures use unique formulations that result in differing markers when the expended powder is analyzed in the infrared spectrum.
As an added benefit, the technique does not destroy the sample, unlike forensic techniques commonly used, Rabalais said.
The Journal of Forensic Sciences is dedicated to the publication of original investigations, observations, scholarly inquiries, and reviews in the various branches of the forensic sciences. These include pathology and biology, toxicology, psychiatry and behavioral sciences, general, odontology, physical anthropology, jurisprudence, criminalistics, questioned documents and engineering sciences. The journal also includes similar submissions dealing with forensic-oriented aspects of the social science.
The journal is the official publication of the American Academy of Forensic Sciences, an organization dedicated to the improvement of the administration and achievement of justice through the application of science to the processes of law.
Lamar University offers a bachelor of science in forensic chemistry. "Forensic training will help alleviate the shortage of trained forensic experts in Texas and surrounding states," Rabalais said.
The department recently hired Christopher Chen from Hunter College at the City University of New York. Chen, who holds a Ph.D. in analytical chemistry and a master's degree in forensic science, is a noted researcher in the field of forensic chemistry.
"We are excited to see the department continue to grow," Rabalais said. "The publication of scholarly research in prestigious publications like the Journal of Forensic Sciences brings credit to the department and will help us recruit faculty, students and future research grants."
