Which development method is commonly used for latent fingerprints on nonporous surfaces?

Which development method is commonly used for latent fingerprints on nonporous surfaces?

• A. Cyanoacrylate fuming
• B. Ninhydrin
• C. Physical Developer
• D. Iodine fuming

Answer: (A)

When working with latent fingerprints on nonporous surfaces, cyanoacrylate fuming is the method that yields the clearest, most durable ridge detail. The vapors from cyanoacrylate react with moisture and amino acids in the fingerprint residue, forming a white polymer that adheres to the surface and to the ridge patterns. This creates a stable, high-contrast print that can be photographed and enhanced with dyes, powders, or fluorescence, and it works well on materials like glass, metal, and plastic.

Other methods target different substrate types or have drawbacks on nonporous surfaces. Ninhydrin reacts with amino acids but is suited to porous substrates like paper, where prints can diffuse through the material; on nonporous surfaces it often fails to produce a clear or lasting print. Physical Developer is also used mainly for porous substrates and can be ineffective or destructive on nonporous items. Iodine fuming can visualize prints briefly on some materials but the results are temporary and prone to fading, which makes it less reliable for long-term documentation.