Which of the following is a method used to visualize latent prints?

Ultraviolet (UV) light is a widely used method to visualize latent prints due to its ability to reveal prints that are otherwise invisible to the naked eye. When latent prints are deposited on surfaces, they can be composed of various residues, including oils and sweat, which can fluoresce under UV light. This property allows investigators to enhance the visibility of these prints, making it easier to capture and analyze them. Utilizing UV light can improve the chances of detecting prints on a variety of surfaces, especially non-porous surfaces like glass or plastic, where traditional visualization methods may be less effective.

The other methods listed are not typically employed for latent print visualization in forensic investigations. CT scanning and magnetic resonance imaging are primarily used in medical imaging and are not suitable for examining fingerprints. Thermal imaging detects heat patterns but does not highlight the chemical composition of a latent print. Thus, UV light remains an essential tool in the arsenal of forensic experts for enhancing the visibility of latent fingerprints.