Blood identification and discrimination between human and nonhuman blood using portable Raman spectroscopy.

Area of Science:

• Forensic Science
• Analytical Chemistry
• Spectroscopy

Background:

• Raman spectroscopy is a nondestructive technique for molecular structure identification.
• It has emerged as a versatile analytical method for forensic applications.
• Portable spectrometers enhance field applicability for forensic analysis.

Purpose of the Study:

• To evaluate the efficacy of portable Raman spectroscopy for blood identification.
• To discriminate between human and nonhuman bloodstains using this technique.
• To assess the method's utility in real-world crime scene scenarios.

Main Methods:

• Raman spectra were acquired from bloodstains of 11 different species using a portable Raman spectrometer.
• Key Raman peaks characteristic of blood were identified across all species.
• Principal component analysis was employed to distinguish human from nonhuman blood.

Main Results:

• Characteristic Raman peaks for blood were consistently observed in all 11 species.
• Principal component analysis successfully differentiated human bloodstains from nonhuman ones.
• The method proved effective for analyzing bloodstains up to 3 months old.

Conclusions:

• Portable Raman spectroscopy is a viable tool for blood identification in forensic settings.
• The technique enables discrimination between human and nonhuman blood at a crime scene.
• This method offers a rapid, nondestructive, and field-deployable solution for forensic blood analysis.