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Raman Spectroscopy for Analyzing Body Fluid Traces: Moving Towards a Practical Forensic Application

NCJ Number
Date Published
July 2018
18 pages
This is the Final Summary Overview of the findings, methodology, and implications for criminal justice of a research project with the goal of further developing a method for the identification and characterization of body fluid traces using Raman spectroscopy, including determination of the limit of detection, the identification of biological stains on various substrates, the investigation of potential false positives, and determining the donor's age.

Using a previously built model for the identification of body fluids using Raman spectroscopy, this study determined that Raman spectroscopy is sufficiently sensitive to detect a single red blood cell (RCB), which is more sensitive than DNA profiling by several orders of magnitude. Semen stain was identified on glass and blue polyester, using the Raman spectroscopy method. For all analyzed fluids (dry blood, saliva, and semen), the results show that the Raman spectroscopy method is selective and shows no false positives, making it advantageous over current presumptive tests. In addition, Raman spectroscopy combined with advanced statistical analysis showed promise for differentiating groups of donors based on their age; however, further work is needed to complete this part of the study. By significantly increasing the amount of information obtained, while reducing the cost and time of analysis, as well as preserving evidence integrity in a non-destructive confirmatory test, the proposed Raman spectroscopy method is superior to existing procedures for analyzing body fluid traces. Also, the development of portable instrumentation would significantly improve the efficiency of crime-scene investigations. Scholarly products and conference presentations on this project are listed.

Date Published: July 1, 2018