How are latent prints characterized?

Latent prints are characterized primarily by being invisible to the naked eye until they are enhanced through various means, such as powders or chemical treatments. This invisibility is due to the fact that latent prints are formed from the natural oils and sweat from a person's fingertips, which do not leave an obvious mark on surfaces.

The process of enhancing these prints is crucial in criminal investigations, as it allows forensic experts to reveal the unique patterns of ridges and valleys that make up a fingerprint. This is essential for identification purposes, especially in scenarios where a visible print is not available.

Other options do not accurately describe latent prints. They are not directly visible, which rules out the first option. While light may help in the enhancement process, the second option incorrectly implies that they only exist in the presence of light. Lastly, latent prints can be found on a variety of surfaces, so the idea that they are only found on certain surfaces is misleading. Thus, the correct characterization of latent prints focuses on their invisibility and the need for enhancement techniques to make them observable.