Ridge Width Correlations between Inked Prints and Powdered Latent Fingerprints

Abstract

A methodology to estimate the time of latent fingerprint deposition would be of great value to law enforcement and courts. It has been observed that ridge topography changes as latent prints age, including the widths of ridges that could be measured as a function of time. Crime suspects are commonly identified using fingerprint databases that contain reference inked tenprints (flat and rolled impressions). These can be of interest in aging studies as they provide baseline information relating to the original (nonaged) ridges' widths. In practice, the age of latent fingerprints could be estimated following a comparison process between the evidentiary aged print and the corresponding reference inked print. The present article explores possible correlations between inked and fresh latent fingerprints deposited on different substrates and visualized with TiO . The results indicate that the ridge width of flat inked prints is most similar to fresh latent fingerprints and these should be used as the comparison standard for future aging studies.

A Small Population Study on Friction Skin Ridges: Differences in Ridge Widths Between Latent and Inked Fingerprints

“…In this report, a carbon black powder-which develops ridges in black-and a titanium dioxide (TiO 2 )-based powder-which develops ridges in white-will be the focus of the analysis, together with flat and rolled inked prints. This work further develops previous studies in using ridge width as morphometric (10). In this case, exemplar inked prints from known individuals provide a reliable source of ridge width information that could be used as a "fresh reference" for comparisons with the respective fresh and aged latent fingermarks.…”

“…According to previous research, as latent fingermark ages, substantial visual and chemical changes occur that affect, in different ways, the morphology of the friction ridges . The technique known as morphometrics incorporates the analysis of shape and size of the ridges and could be a useful technique to assess the aging process of latent fingermarks, particularly to identify variations in ridge widths that occur over time . This feature could be potentially used as a parameter to study the natural aging process of latent fingermarks and, eventually, help estimate the time of deposition at a crime scene using a fully automated system.…”

“…KEYWORDS: forensic science, ridge width, color contrast, titanium dioxide, carbon black, correlation, age Fingerprints have been used for over 100 years for human identifications, and they are still used as a valuable forensic tool to place a suspect at the crime scene. Not until recently, the scope of research has expanded to incorporate a wider array of analysis of fingermarks, including chemical examinations of sweat components (1-3); gender determination (4); and age estimation of evidence from chemical and visual perspectives (5)(6)(7)(8)(9)(10)(11).…”

“…According to previous research, as latent fingermark ages, substantial visual and chemical changes occur (5)(6)(7)(8)(9)(10)(11)(12)(13) that affect, in different ways, the morphology of the friction ridges (6)(7)(8)(9)(10)(11). The technique known as morphometrics incorporates the analysis of shape and size of the ridges and could be a useful technique to assess the aging process of latent fingermarks, particularly to identify variations in ridge widths that occur over time (10,14).…”

“…Thus, while this was a solid preliminary study on the analysis of the widths of ridges as an aging parameter, there is still more research needed to investigate the reliability of this parameter as a predictor of age. A previous study by De Alcaraz‐Fossoul et al touched on determining correlations between latent fingermarks and inked exemplars. This study used only one donor for deposition of fingerprints and utilized three examiners to measure the ridge widths.…”