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Geoprofiling isotopic analyses provide investigative leads for unidentified human remains cases by determining possible regions of origin or excluding unlikely residences during life, which in turn can reduce the number of missing persons an investigator mustconsider. However, maceration methods involving heat, bleach, baking soda, and detergents have much potential to significantly change biogenic isotopic values in the structural carbonate phase of bone bioapatite. Here we test the impact of seven maceration methods on δ13C and δ18O values of bone carbonate (BC) of pig (Sus scrofa) ribs. Four of the seven maceration methods altered pig δ13CBC values with offsets ranging from 0.4‰ to 1.4‰; this amount of change would not severely impact human diet or geolocation interpretations. Five of the methods significantly decreased pig δ18OBC values by averages ranging between 1.0‰ and 2.6‰ likely due to the isotopic exchange between bone and heated water. As an illustrative exercise, we compared our study’s results to macerated rib δ13CBC and δ18OBC values of an identified New York City resident previously in the custody of the New York City Office of Chief Medical Examiner (NYC OCME). We suggest that maceration methods, especially those involving heated water, can potentially contribute to erroneous geolocation estimates garnered from rib δ18OBC values of unidentified individuals. 

Isotopic analyses of human remains augment the biological profile with geolocation and dietary information, furthering efforts to identify unknown individuals from a forensic context. Here we test the methodological resolution of geolocation (δ18O, 87Sr/86Sr) and dietary (δ13C, δ15N) isotopes of one identified individual who immigrated to New York City from St. Vincent and the Grenadines (SVG), Lesser Antilles. Isotope-based geolocation estimates did not identify the childhood residency on SVG, but did point to New York City as a possible residence during early adulthood. The individual’s C3-based diet did not significantly change from childhood to early adulthood, illustrating the maintenance of food traditions after the immigration event. This study illustrates that further development of tissue-specific isoscapes incorporating bioavailable foods, drinking water, and cultural traditions is warranted to refine methodological resolution of isotopic applications in forensic anthropology.