Edwin L. Aguirre
When crime-scene investigators want to determine if the soil found in a suspect’s shoes matches the dirt where a victim’s body was found, they turn to forensic geology.
This field of study is also useful in determining if a victim was killed at one location and the body moved to another (based on sand or soil particles on the victim’s skin or clothing), and for detecting underground gravesites. But forensic geology is vital in more than just homicide investigations - it is also instrumental in cases involving mining and mineral or gem fraud.
Environmental, Earth and Atmospheric Sciences Prof. Nelson Eby, who teaches a course in Forensic Geology, recently spent a week in Bogota, Colombia, assisting the country in its efforts to establish an Instrumental Neutron Activation Analysis Laboratory for use in criminal investigations.
Neutron Activation Analysis (NAA) is a very sensitive, highly accurate and reliable analytical technique for determining concentrations of major, minor or trace elements in samples ߞ; such as soil, gunshot residue, bullet or glass fragments, paint specks, hair, etc. ߞ; typically found at crime scenes. In addition to forensic investigations, NAA is also used in archeology, art and historical artifact research, biochemistry, epidemiology, geological science, semiconductor materials and soil science.
While in Bogota, Eby presented an all-day seminar on the use of geology and various analytical methods in forensic investigations. “My hosts were INGEOMINAS and the Instituto Nacional de Medicina Legal y Ciencias Forenses,” he says. “The latter group is the national forensic laboratory for Colombia.”
In addition to international outreach, Eby says this effort also involves other disciplines of the University. “I have recently modernized our gamma-ray spectroscopy laboratory, which is used for Neutron Activation Analysis,” he says. “I use the facilities of the Radiation Laboratory, specifically our research reactor. We anticipate that this program will be an ongoing collaboration with the Colombians.”