Forensic work where CEFOP decodes the path of gunpowder

Atomic Spectroscopy Laboratories, Faculty of Chemical Sciences, and the Photoacoustic of CEFOP, are working in collaboration with the Investigative Police (PDI), in a project that can be applied in the forensic field, and in the environment.

Photoacustic LaboratoryA particle of gunpowder-only 100 microns is sufficient for a Photoacoustic Laboratory researcher of our center to determine what type of powder is what brand and when it collided with. Such capabilities, and a relationship in previous work, were what prompted PhD. Jorge Yanez, teacher and researcher in the Department of Analytical and Inorganic Chemistry, Faculty of Chemistry, and PhD. Renato Saavedra to explore the analytical potential of photothermal methods in forensics area.

“This is a scientific collaboration between two laboratories, that of Photoacoustic of CEFOP, and Atomic Spectroscopy, Faculty of Chemistry. The aim is to develop analytical methods that can be applied both in the forensic field, as in the environmental area”, said Dr. Yanez, who visited the Photoacoustic Laboratory, along with members of the Police Department of Concepción and Santiago, taking advantage their participation in a seminar at the University of Concepción.

Doctor in Chemistry said the work being done is based on the determination of trace and ultra-trace, this means, compounds that are in extremely low concentrations, either in the environment or arising from a criminal action. “The idea is to take those samples for offer scientific evidence to chemical experts, as evidence, to check if a person fired, what brand shot, when fired, and how the crime took place. That in the forensic sense”, said Jorge Yanez.

In one proof, a world

PhD. Renato SaavedraTo develop this project, a chemistry degree student, Valeria Zuniga, joined to the team, and she moves in both laboratories. Dr. Renato Saavedra, from Nondestructive Characterization of Materials in CEFOP, said the work being done in the laboratory is given in the context that “each sample, is a challenge and involves knowing the language of the specialty, to study the details of its origin and composition, introduce forensic analysis, and try to find some important features in low sample, to try to identify and provide some systematic information for decision-making”. In this research they have also applied multivariate analysis tools, “which allows us to reduce amount of data, for example, the complex spectra reduced to 2 or 3 relevant features,” said Saavedra.

This project carried Valeria Zuniga to going out and knows other areas out of the lab and even firing ranges in the PDI to sample firsthand. In this context, Renato Saavedra explained that with these data gunpowder, more samples has forwarded the same PDI, have been able to identify several spectra of powder, of different brands and many ammunitions, “we may tell based on the photoacoustic for example, who is the manufacturer of gunpowder”.

The researcher of our Center explained that the photoacoustic technique doesn’t require sample preparation and is very simple. “To the Police Department is attractive in principle because it is collecting and measuring powder. The novelty is that with a new detector we are using, we can detect grain gunpowder, about 100 microns, and make decisions. Currently we are working with residues, which is much less”.



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