In forensic science, iodine is primarily used as a chemical reagent for “iodine fuming,” a technique to develop latent fingerprints on various surfaces by exposing them to iodine vapors, which react with the oils present in fingerprints, causing them to appear as a brown image; this method is particularly useful for porous surfaces like paper and cardboard, but needs to be photographed quickly as the prints will fade due to the volatile nature of iodine vapors.
Key points about iodine in forensics:
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Function:
Iodine fuming is one of the oldest methods for developing latent fingerprints.
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Mechanism:
Iodine vapors physically adsorb to the oils in fingerprints, creating a visible brown coloration.
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Surface suitability:
Works well on porous surfaces like paper, cardboard, and unpainted wood.
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Limitations:
- Temporary prints: Developed fingerprints with iodine quickly fade due to the volatile nature of iodine.
- Not for metal surfaces: Iodine can corrode metal surfaces, making it unsuitable for fingerprint development on metal objects.
- Requires quick action: Developed prints need to be photographed immediately after development.
- Temporary prints: Developed fingerprints with iodine quickly fade due to the volatile nature of iodine.
