Patent fingerprints are created under which condition?

• A. When a foreign substance transfers and makes readily visible fingerprints
• B. When prints are visible without transfer
• C. When a surface is etched to reveal prints
• D. When a surface is irradiated to reveal prints

Answer: (D)

Patent fingerprints are visible impressions formed when a foreign substance transfers from the finger to a surface, making the print readily visible without any special development. This direct transfer creates a print you can see with the naked eye, which distinguishes patent prints from latent prints that require processing to become visible. The other scenarios describe ways to reveal prints that aren’t created by a simple transfer: irradiation or etching are methods used to visualize prints that aren’t initially visible, and prints visible without any transfer don’t reflect the transfer of material that defines patent prints.