Migration, violence, and the “other”: A biogeochemical approach to identity-based violence in the Epiclassic Basin of Mexico

•Geographic origin was a critical indicator of social difference in Mesoamerica.•87Sr/86Sr results find 70% of victims were non-local to the Basin of Mexico.•Interlaboratory variability in δ18O prohibits paleomobility analysis at Non-Grid 4.•Migrants at Non-Grid 4 originated from various geologically distinct regions.•Sacrificed individuals were targeted for violence based on their divergent origins.