Fingermark visualisation on uncirculated £5 (Bank of England) polymer notes: Initial process comparison studies

Area of Science:

• Forensic Science
• Chemistry
• Materials Science

Background:

• Polymer banknotes present unique challenges for fingermark visualization due to their non-porous surface.
• Established fingermark visualization techniques may not be optimal for novel polymer substrates like the Bank of England's £5 note.

Purpose of the Study:

• To assess the efficacy of various fingermark visualization processes on new, uncirculated Bank of England £5 polymer banknotes.
• To identify the most effective methods for enhancing latent fingermarks on this specific currency.

Main Methods:

• Fourteen different fingermark visualization processes were applied to £5 polymer banknotes.
• Processes included standard 'Category A' methods and newer techniques like fpNatural® 2 powder and vacuum metal deposition.
• Fingermarks were examined under white light, fluorescence, reflected infrared imaging, and after lifting.

Main Results:

• fpNatural® 2, multimetal deposition, Wet Powder™ Black, iron oxide powder suspension, and black magnetic powder demonstrated high effectiveness.
• These top-performing methods remained effective when combined with infrared imaging and lifting techniques.
• Results varied slightly depending on the specific visualization process and viewing conditions.

Conclusions:

• Several fingermark visualization techniques show significant promise for use on Bank of England £5 polymer banknotes.
• Further research is recommended to develop comprehensive operational guidance for forensic practitioners.
• The study provides foundational data for optimizing fingermark detection on polymer currency.