The Effect of Varying the Composition of Fingerprint Sweat Deposits on the Corrosion of Brass and Fingerprint Visibility.
Corrosion of α-phase brass by sebaceous sweat fingerprint deposits produced identifiable impressions in a majority of samples (n = 40) 4 days after deposition. Combining sebaceous with eccrine sweat yielded a greater percentage of identifiable fingerprint deposits, although this increase was not statistically significant. Production of identifiable fingerprints from eccrine sweat deposits was dependent on the sampling time of year with deposits taken during summer months giving similar percentages of identifiable fingerprints to sebaceous deposits. A statistically significant positive correlation was found between elapsed days after deposition and identifiable eccrine (ρ = 0.787, p < 0.05), sebaceous (ρ = 0.724, p < 0.05), and eccrine/sebaceous mixture (ρ = 0.908, p < 0.01) fingerprints deposited during summer months. The summer increase in the percentage of identifiable eccrine sweat deposits was statistically significant compared to winter eccrine deposits (p < 0.0001). Observations were consistent with results obtained from artificial sebaceous and eccrine sweat.
Department of Physics & Astronomy, University of Leicester, University Road, Leicester, LE1 7RH, U.K.
Alice
A
Cooper-Dunn
Northampton School for Boys, Billing Road, Northampton, NN1 5RT, U.K.
Owen
O
Jones
Department of Criminology, University of Leicester, 154 Upper New Walk, Leicester, LE1 7QA, U.K.
John W
JW
Bond
brass; eccrine sweat; fingerprint visibility; forensic science; galvanic corrosion; sebaceous sweat