North-Central Section - 54th Annual Meeting - 2020

Paper No. 11-5
Presentation Time: 8:30 AM-5:30 PM


VEST, Jordan1, PATRICK, Jessica1, DAWSON, Claudia2, SEIBERT, Zoey1, MCLEOD, Claire1 and KREKELER, Mark P.S.1, (1)Department of Geology and Environmental Earth Science, Miami University, Oxford, OH 45056, (2)Department of Geology & Environmental Earth Sciences, Miami University - Hamilton, 1601 University Blvd., Hamilton, OH 45011

Combating violence against women, abductions and human trafficking are of high interest globally. One aspect of these efforts is the development of methods that link victims and perpetrators through rapid data acquisition technologies that can be used in the field or lab. The majority of makeup products commonly worn by women have a complex mixture of numerous industrial materials from various sources. These materials result in distinct reflective spectra that can be applied within the context of forensic investigation. Reflective spectroscopy techniques offer a non-destructive means to quickly analyze and characterize evidence both in the field and in the lab. This project investigates 1.) the individual spectral properties of a variety of makeup samples and 2.) the spectral properties of makeup products when they are applied to a variety of substrates under various conditions. Substrates were chosen to represent a residential setting and include carpet, tile, flooring, and other materials. An ASD spectroradiometer was used in an open path geometry to measure reflective spectra of makeup, substrate. and makeup-substrate combinations. Samples of makeup tested thus far appear largely to be spectrally distinct from human skin, numerous clothing items, and several common substrates (e.g., brick, wood, Ottawa sand). Initial experiments of makeup smudges on carpet, meant to mimic forceful contact or victim dragging, are shown to be distinct from carpet substrates alone. Even when color tones of makeup are visually similar to carpet, there are significant spectral differences, although these differences may best be discerned through first derivative comparisons of substrate and makeup end members. Initial work indicates 0.03 g/cm2 is easily detectable in a short open path geometry. Preliminary results of this investigation indicate reflective spectroscopy may be a useful and versatile technique for non-destructive detection of makeup within the context of forensic investigations, provided that a robust spectral library is developed and a field method can be codified.