Which latent print development technique is best for non-porous surfaces contaminated with grease?

The technique that is best suited for developing latent prints on non-porous surfaces contaminated with grease is Sudan Black. This dye is particularly effective in visualizing fingerprints that have been compromised by oily or greasy substances, which can occur on surfaces such as glass, plastic, and metal.

Sudan Black works by adhering to the lipid components found in fingerprints, allowing the impression to become visible against the non-porous background. This makes it a crucial technique in forensic science, especially when dealing with prints that are not easily seen due to contamination.

In contrast, while other techniques like ninhydrin and silver nitrate are excellent for porous surfaces, they do not perform well on greasy residues. Ninhydrin reacts with amino acids but requires moisture that may not be present in greasy prints, and silver nitrate is primarily used for developing prints on porous materials like paper. Superglue, or cyanoacrylate, is effective for developing prints on non-porous surfaces, but it is not specifically designed for oily prints. While it can be used to visualize prints, it is less ideal than Sudan Black in scenarios where grease is a major factor.

Understanding the properties and applicability of each development technique is essential for effective latent print examination, making Sudan Black