Fingerprints left on smooth nonporous surfaces such as glass can be developed using what?

• A. Dusting powder
• B. Cyanoacrylate fuming
• C. Ninhydrin
• D. Fluorescent powder

Answer: (D)

On smooth nonporous surfaces, the key is producing a signal that stands out against the shiny background. Fluorescent powders do this by containing additives that glow under ultraviolet or alternate light. When the powder adheres to the oily fingerprint residues, the ridges become coated, and under the right lighting the coated ridges emit bright fluorescence while the glass background remains relatively dark. This high contrast makes the fingerprint pattern much easier to see and photograph for comparison, especially on surfaces like glass that can wash out or obscure prints under normal light. The fluorescence can be captured with appropriate cameras or filters to preserve the detail needed for analysis, making fluorescent powder a strong option for visualizing latent prints on smooth, nonporous materials.