An investigation into the enhancement of sea-spray exposed fingerprints on glass

• We exposed prints on glass to sea spray aerosol (SSA) for 1 week and 1 month.
• Enhanced with 11 different fingerprint powders and powder suspensions.
• Less identifiable prints found after exposure for 1 month (11%) cf. 1 week (69%).
• Iron oxide and Wetwop™ white were better at enhancing prints exposed to SSA.

Fingerprints are considered one of the best forms of personal identification. While numerous enhancement techniques exist to develop fingerprints under various conditions, the enhancement of fingerprints exposed to sea spray aerosol (SSA) still remains problematic.1056 fingerprints from four donors, using a depletion series and triplicate repeats, were deposited onto glass panels and exposed to SSA for 1 week and 1 month.Control prints were deposited in the same manner and left under laboratory conditions.All prints were enhanced using fingerprint enhancement techniques available to Forensic Police Officers and subsequently examined for identifiability by a Fingerprint Expert.Significantly fewer identifiable prints (p < 0.01) were developed after exposure to SSA for 1 month (11%) compared to exposure for 1 week (69%) (compared to the control prints 99%) for all enhancement techniques.After 1 week's exposure, all techniques enhanced over 50% of prints, except SPR white (12%), with iron (III) oxide and Wetwop™ white producing over 90% identifiable prints.Only iron (III) oxide, Wetwop™ white and SPR black returned any identifiable prints following 1 month's SSA exposure. Iron (III) oxide being significantly better (p < 0.01, 67%) than the other techniques.Iron (III) oxide suspension and Wetwop™ white were found to be superior at enhancing prints at both SSA exposure times.