Monthly Meeting

Technical Program

“Application of Particle Correlated Raman Spectroscopy (PCRS) for the Forensic Examination of Soil Minerals”

Soil is a valuable trace which, when properly recognized, analyzed and interpreted, has the potential to provide investigative leads and to associate an unknown specimen with a collected known. Although this is widely recognized by criminalists with a plethora of case examples, criticisms of forensic soil analysis as being subjective, too labor-intensive, and too time-consuming have resulted in a considerable decline in its use in forensic investigations. As a result, exemplar soil samples are not being collected in the field which eliminates the possibility of later laboratory analysis. Further, forensic laboratories are not equipped with criminalists who are currently capable of performing a comprehensive forensic soil examination. Thus, the potential of soil traces is not being realized. The purpose of this presentation is to share our research steps and progress in developing a statistically-supported, automated, and objective analytical method for forensic soil analysis using particle correlated Raman spectroscopy (PCRS). PCRS, also known as particle driven or morphologically directed Raman spectroscopy (MDRS), is a novel yet reliable analytical technique that is capable of delivering particle size distribution and microscopic morphological characteristics for the particles present within a sample (e.g., minerals), and at the same time provides secure chemical identification. To develop PCRS for inclusion in a forensic soil workflow, the limitations and advantages of the method (e.g., dispersion, sample imaging and analysis, Raman spectroscopic analysis and interpretation) need to be evaluated, which has been the goal of the research that will be presented.