Latent Fingermark Aging Patterns (Part III): Discontinuity Index as One Indicator of Degradation |
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| Authors: | Josep De Alcaraz‐Fossoul Ph.D. Carme Barrot Feixat Ph.D. Clara Carreras‐Marin M.Sc. Jack Tasker B.Sc. Sara C. Zapico Ph.D. Manel Gené Badia Ph.D. |
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| Affiliation: | 1. New College of Interdisciplinary Arts and Sciences, School of Mathematical and Natural Sciences, Arizona State University, Glendale, AZ 85306;2. Legal Medicine Unit, Faculty of Medicine, University of Barcelona, 08036 Barcelona, Catalonia, Spain;3. Department of Applied Forensic Sciences, Mercyhurst University, Erie, PA 16546 |
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| Abstract: | This article is the third in a series of reports exploring quantifiable visual parameters of the aging process of latent fingermarks. On this occasion, research is focused on the occurrence of ridge discontinuities (i.e. breakages) as a function of time. Experiment variables included type of secretion (eccrine and sebaceous), substrate (glass and plastic), and exposure to natural light (dark, shade, and direct light) over a 6 months period. Fingermarks were sequentially visualized with titanium dioxide powder, photographed, and the number of naturally occurring ridge discontinuities subsequently evaluated. A semi‐quantitative value, named Discontinuity Index, was used to better characterize this aging parameter. Results indicated that ridges of sebaceous depositions on glass were generally less affected by the environmental conditions compared with those on plastic surface. In addition, aging in darkness was not always the best condition for preservation, and the direct exposure to light seemed not to affect the degradation under certain conditions. |
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| Keywords: | forensic science aging discontinuities latent fingerprint dating titanium dioxide parameters morphometrics |
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