Which method has solved arson cases by revealing latent prints, despite being impractical in other contexts?

The method that has successfully solved arson cases by revealing latent prints is heat. In the context of arson investigations, heat can cause the residues from sweat and oils on a person's skin to become more pronounced on surfaces that are otherwise difficult to examine for fingerprints. When a surface is exposed to intense heat, it can sometimes result in the release of latent prints that are otherwise not visible under normal conditions.

This technique is particularly valuable in arson scenarios where traditional fingerprinting methods may fail due to the extensive damage caused by fire. The high temperatures can reveal impressions that are critical for identifying suspects. Though the use of heat as a method for enhancing latent prints may not be practical in other contexts—such as in standard fingerprint recovery from intact surfaces—it finds its niche in forensic investigations related to fire.