Femoral Neck Axis Length (FNAL): Use in Biological Profiles of Deceased Undocumented Immigrants

Since 1998, the bodies of more than 6300 undocumented immigrants have been discovered along the US-Mexico border. The Reuniting Families Project (RFP) is an effort to recover, identify, and repatriate these remains. To begin the identification process, forensic anthropologists utilize population specific standards in the development of biological profiles. Ancestry and sex estimations are two important elements of these profiles. New, population-specific methodologies are always needed which can further improve the accuracy of these estimates. In this study, the femoral neck axis length (FNAL) was examined to determine its potential use in sex and ancestry estimations of undocumented border crossers (UBCs). Comparison samples included: 87 American Black, 108 American White, 91 Native American, and 58 UBC specimens. When classifying samples into ancestral groups with discriminant function analysis, FNAL provided very low classification accuracies, ranging from 34.7% to 40.4%. However, when classing samples into males and females with DFA, FNAL provided high classification accuracies ranging from 83.4% to 91.4%. The sectioning point then calculated for UBCs, in particular, provided an averaged classification rate of 89.85%. The results of this study show considerable promise for the future use of FNAL in forensic anthropology.