Since substrate interference presents a significant challenge in characterizing body fluid traces with Raman spectroscopy at a crime scene, the current project explored several possible solutions, including the selection of laser excitation, isolating the signal of blood using spectral subtraction, and using a favorable substrate for collection that minimizes interference.
Simulated blood stain evidence was prepared and analyzed using a Raman microscope with variable laser capabilities. The findings indicate that the best approach for detecting blood depends on the nature of the substrate and the type of interference encountered. (publisher abstract modified)