A suspect's hands are swabbed after a shooting incident. Which technique is currently accepted as the confirmatory method for identifying gunshot residue particles?

• A Dermal nitrate (paraffin cast) test
• B Neutron activation analysis alone
• C Flame photometry for potassium
• D Scanning electron microscopy coupled with energy dispersive X-ray analysis ✓

Explanation

SEM-EDX identifies particles that are simultaneously spheroidal in morphology and composed of lead, barium and antimony, a combination considered characteristic of gunshot primer residue. This morphological plus elemental confirmation avoids false positives from occupational exposure. The paraffin test detects nitrates and gives false positives with fertilisers, tobacco and cosmetics, which is why it was abandoned. Neutron activation analysis lacks particle-level specificity when used alone.

Reference: Knight's Forensic Pathology, 4th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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