Temporal Patterns of Mexican Migrant Genetic Ancestry: Implications for Identification

Motivated by the humanitarian crisis along the US–Mexico border and the need for more integrative approaches to migrant death investigations, we employ both biological and cultural anthropology perspectives to provide insight into these deaths and the forensic identification process. We propose that structural vulnerabilities linked to ethnicity impact the success of identifying deceased migrants. Using forensic genetic data, we examine the relationships among identification status, case year, and ancestry, demonstrating how Native American and European ancestry proportions differ between identified and unidentified migrant fatalities, revealing an otherwise unrecognized identification bias . We find that Mexican migrants with more European ancestry are more often successfully identified in recent years. We attribute this bias in identification to the layers of structural vulnerability that uniquely affect indigenous Mexican migrants. By demonstrating the impact that social processes like structural violence can have on the relative success of forensic casework along the US–Mexico border, our work underscores the fact that forensic casework is itself a social process. Research undertaken with the intent to improve forensic identification protocols should consider social context, a factor that could significantly impact identification rates. This study shows the need for collaboration between forensic practitioners and those working closely with affected communities. [ US – Mexico border, forensic anthropology, migration, admixture, DNA ]