What chemical method is used for developing prints on nonporous surfaces?

Fuming with cyanoacrylate is an effective chemical method for developing latent fingerprints on nonporous surfaces, such as glass, plastic, and metal. This technique involves exposing the nonporous item to fumes produced by cyanoacrylate, a type of adhesive commonly known as super glue. The vapors adhere to the moisture and oils contained in the fingerprint residue, leading to a visible white impression of the fingerprint once the fumes solidify.

This method is favored because it provides clear, durable prints that can be photographed or further analyzed. It is particularly useful in forensic investigations where latent prints can be crucial evidence linking a suspect to a crime scene. The other methods mentioned, while effective in different contexts, are not suited for nonporous surfaces. For instance, iodine fuming is more suitable for porous items, ninhydrin reacts with amino acids in porous surfaces, and silver nitrate is typically used for developing prints on various surfaces but is less effective on nonporous materials compared to cyanoacrylate fuming.