Fingermark ridge drift: Influencing factors of a not-so-rare aging phenomenon.

Fingermark ridge drift is a random modification of (aged) fingermark patterns at a ridge scale. This phenomenon was previously proven to alter key elements used for identifications, such as the appearance of minutiae. Little is currently reported on the underlying factors contributing to its occurrence.

Repeatability and reproducibility of the color contrast technique for fingermark age estimation applications.

This research complements previous studies in which color contrast between ridges and furrows of latent fingermarks was investigated as a potential aging parameter. In this case, the robustness of the technique has been tested by including five female and five male donors who deposited sebaceous-rich latent fingermarks onto ceramic tile and polystyrene plastic as well as flat and rolled inked fingerprints on commercially available ten-print cards. Fresh latent fingermarks were visualized with either carbon black or titanium dioxide powder (TiO ) and inked fingerprints were imprinted in succession without re-charging ink.

Evaluation of latent fingermark color contrast as aging parameter under different environmental conditions: A preliminary study.

This research expands previous studies in which color contrast between ridges and furrows of powder-enhanced latent fingermarks was explored as a possible aging parameter. The main goal is to test the sensitivity of the technique across a predetermined set of factors. In this case, experiment factors have included two donors who deposited sebaceous- and eccrine-rich fingermarks onto ceramic tile and polystyrene plastic.

Identification of polygonal barrel rifling characteristics in bullet wipe residue deposited on textiles.

This study examines the potential formation of land and groove rifling characteristics in bullet wipe residue deposited on textile fabrics. Textile fabrics comprised of natural, synthetic, semi-synthetic, and blended fibers were damaged either individually or as triplicate layers using two different ammunition types: Winchester WinClean 115 grain 9 mm Luger BEB and Speer 115 grain 9 mm Luger TMJ. Each ammunition type was fired in triplicate using a 9 mm Luger caliber Glock 17 at a distance of approximately 6 feet at normal incidence to the target.

The Capability of Raman Microspectroscopy to Differentiate Printing Inks.

This study applies Raman microspectroscopy to differentiate the chemical components in printing inks of different brands, colors, and type using the 532 nm and 785 nm excitation wavelengths. Spectra were collected from 319 inks (78 inkjet, 76 toner, 79 offset, and 86 intaglio) representing various colors. Comparisons were performed to calculate discrimination capability percentages for each ink type.

A comparison of the effectiveness of swabbing and flossing as a means of recovering spermatozoa from the oral cavity.

This study examined whether flossing the teeth is a more effective collection method in recovering spermatozoa than conventional swabbing techniques. It was hypothesized that inclusion of flossing as a collection method would extend the recovery of spermatozoa to longer postcoital intervals (PCIs). Eighteen individuals provided 174 oral cavity samples.