null
(Ed.)
Fingerprint development has been used to visualize latent prints since the 19th century, and several companies produce a variety of commercially available black fingerprint powders. While the method to develop fingerprints has been refined over the years, the composition of fingerprint powders that are used in print development has not been studied extensively. Six different black fingerprint powders were studied using X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDS), dynamic light scattering (DLS) and zeta potential, attenuated total reflectance infrared spectroscopy (ATR-IR), Raman spectroscopy, powder X-ray diffraction (PXRD), and solution-phase nuclear magnetic resonance spectroscopy (NMR) in addition to a quality study involving certified latent print examiners. When comparing all chemical, physical, and morphological results for the fingerprint powder, this study determined that powders ranked best by latent print examiners are fingerprint powders that mainly contain carbon and oxygen with particle sizes around 50 nm and spherical morphology. Powders with large particle sizes, irregular shape, and elemental compositions consisting of many elements ranked poorly in the quality study performed.
more »
« less