Raman chemical imaging of explosive-contaminated fingerprints

Area of Science:

• Forensic Science
• Analytical Chemistry
• Spectroscopy

Background:

• Forensic investigations often involve analyzing trace evidence like fingerprints.
• Detecting chemical contaminants, such as explosives, on fingerprints is crucial for security.
• Existing methods may be destructive or lack chemical specificity.

Purpose of the Study:

• To develop and demonstrate a non-destructive method for detecting and identifying explosives in contaminated fingerprints.
• To map the spatial distribution of explosives within a fingerprint.
• To ensure the fingerprint remains intact for subsequent biometric identification.

Main Methods:

• Utilizing bright-field imaging to locate regions of interest within fingerprints.
• Employing Raman chemical imaging (RCI) and fluorescence imaging for chemical analysis.
• Applying Pearson's cosine cross-correlation technique for spectral identification (500-1850 cm(-1)).

Main Results:

• Successfully detected and identified explosive residues within contaminated fingerprints.
• Obtained spatial distribution maps of the identified explosives.
• Demonstrated the non-destructive nature of the RCI technique.

Conclusions:

• Raman chemical imaging is a viable non-destructive technique for identifying explosives in fingerprints.
• This method preserves the integrity of the fingerprint for further forensic analysis.
• The technique holds significant promise for enhancing forensic examination of contaminated evidence.