What is the function of iodine in fingerprint development?

Iodine is primarily used in the process of developing fingerprints due to its ability to sublimate, turning from a solid to a gas and then recombining with moisture and other substances on the surface of the latent print. This results in a visual enhancement of the print, making it more visible for analysis.

In particular, iodine vapor can adhere to the oils and fats deposited by fingerprint ridges, resulting in a temporary coloration of the print. However, the development of prints using iodine is especially effective for porous surfaces or materials like paper, and it can also be utilized on non-porous surfaces if the right conditions are met.

While it can develop prints on human skin, the context of iodine's function in forensic applications is more often associated with other surfaces, making its ability to enhance visibility for analysis the key takeaway. Thus, iodine’s role is focused on enhancing visibility rather than its more limited application on specific surfaces or obscuring details, emphasizing its importance in the fingerprint development process.