Development of latent fingermarks by aqueous electrolytes

Area of Science:

• Forensic Science
• Materials Science
• Electrochemistry

Background:

• Latent fingermark detection is crucial in forensic investigations.
• Developing effective methods for visualizing fingermarks on diverse surfaces remains a challenge.

Purpose of the Study:

• To investigate the efficacy of aqueous electrolytic solutions in developing latent fingermarks.
• To explore the interaction between these solutions and various metallic and non-metallic surfaces.
• To analyze factors affecting fingermark quality and permanence.

Main Methods:

• Latent fingermarks were deposited on metallic (copper, aluminum, iron, brass, zinc) and non-metallic (glass, plastic) surfaces.
• Surfaces were treated with aqueous electrolytic solutions.
• Developed fingermarks were analyzed for quality and permanence.
• Influence of deposition time, electrolyte pH, pre-processing wiping, and presence of a second metal were studied.

Main Results:

• Good quality fingermarks were successfully observed on several metallic and non-metallic surfaces.
• Sebaceous marks consistently produced higher quality impressions across all tested surfaces.
• Factors such as time interval, pH, wiping, and presence of a second metal significantly influenced the developed impressions.

Conclusions:

• Aqueous electrolytic solutions show potential for latent fingermark development on a range of surfaces.
• Sebaceous composition is a key factor for successful visualization.
• Electrochemical interactions likely play a role in the observed fingermark development.