Which technique is NOT recommended for lifting a latent fingerprint from a nonporous surface?

• A. Use cyanoacrylate fuming
• B. Apply powder to a wet fingerprint using short, quick strokes
• C. Use magnetic powder
• D. Dusting powder on a dry print

Answer: (B)

On nonporous surfaces, latent fingerprints are developed by methods that preserve ridge detail without smearing. Cyanoacrylate fuming (superglue) creates a polymer deposited on the print, making the ridges visible for photography or lifting, and dusting powders (including magnetic powder) are standard ways to visualize or lift prints once they’re dry. The important caution is moisture. Applying powder to a fingerprint that is wet will cause the moisture to cause the powder to clump and smear, destroying the delicate ridge patterns and making the print unreadable. If a print is wet, the proper approach is to dry it first or use a fixing method like cyanoacrylate fuming to stabilize the print before any powdering. That’s why the technique of applying powder to a wet fingerprint with short, quick strokes is not recommended. The other techniques are appropriate for nonporous surfaces and either dry prints or fix prints before powdering.