What is the simplest lighting technique used to enhance a latent fingerprint?

• A. Direct lighting
• B. Infrared lighting
• C. Oblique lighting
• D. Transmitted lighting

Answer: (C)

Friction ridge patterns become visible when light reveals surface texture. The simplest way to do this is oblique lighting, where the light source hits the surface at a shallow angle. This side lighting creates shadows along the ridges and valleys, producing contrast that makes the print pattern stand out against the background using minimal equipment. Direct lighting from above tends to flatten texture and reduce contrast, making prints harder to see. Infrared lighting, while useful in some cases, requires specialized equipment and processing, not the simplest approach. Transmitted lighting shines light through the object, which isn’t practical for most solid surfaces. With oblique lighting, you get quick, clear visibility of the latent print by emphasizing the tiny height differences of the ridges.