Which method is used to enhance the visibility of fingerprints on a variety of surfaces using chemicals?

The method that enhances the visibility of fingerprints on various surfaces using chemicals is chemical treatment. This approach involves applying specific chemical agents that react with components found in sweat and oils left behind by fingers, thereby revealing hidden prints. Common chemical treatments include ninhydrin for porous surfaces, which reacts with amino acids, and cyanoacrylate fuming for non-porous surfaces, which creates a visible coating around the ridges of the print.

Understanding chemical treatment is essential because it offers solutions for detecting fingerprints on surfaces where other methods may not be effective. For instance, while powder application relies on adhering to the print residue, which can be challenging on certain surfaces, chemical treatment can provide a more definitive enhancement in a wider range of situations, including those where moisture or dirt might obscure prints.

While fluorescent dye can be used to visualize latent prints under specific lighting conditions, it typically requires a prior treatment and may not be effective on all surface types. Similarly, visual inspection is not a method of enhancement but rather an observation technique to identify prints that are already visible.