An efficient strategy to detect latent fingermarks on metallic surfaces

Area of Science:

• Forensic Science
• Materials Science
• Surface Engineering

Background:

• Latent fingermark detection on metallic surfaces remains challenging.
• Utilizing surface topography for preferential material deposition is a novel approach.

Purpose of the Study:

• To develop latent fingermarks on metallic surfaces using metal sputtering.
• To optimize magnetron sputtering parameters for preferential deposition onto fingerprint ridges.
• To evaluate the effectiveness of copper and gold thin films for fingermark development.

Main Methods:

• Intentional fingermarks were placed on stainless steel substrates.
• Copper and gold thin films (20-30 nm) were deposited via magnetron sputtering.
• Developed fingermarks were analyzed visually and using optical and scanning electron microscopy.
• Thin film morphology was examined using high-resolution scanning electron microscopy.

Main Results:

• Preferential deposition of copper and gold thin films successfully developed latent fingermarks.
• Gold films demonstrated superior performance, especially for aged (one-month) fingermarks.
• Gold deposition allowed for the detection of ridge contours and minutiae features.
• Copper films exhibited a featureless morphology, while gold films showed discontinuous surfaces and columnar structures.

Conclusions:

• Magnetron sputtering of thin metal films is a viable technique for latent fingermark development on metallic substrates.
• Gold thin films offer significant advantages for developing and preserving aged fingermarks, enhancing forensic identification.
• The optimized sputtering process and film morphology are critical for successful fingermark visualization.