The combined effects of a dry, hot environment and the remoteness of some of the routes used by illegal border crossers can quickly render a person who dies in this environment unidentifiable by visual means. The Office of the Medical Examiner uses two levels of identification, "positive" and "circumstantial." For a positive identification to occur there must be one of two scenarios. Someone who knows the decedent provides the means of identification, usually through visual recognition of the face; or a qualified medico-legal investigator conducts a point-by-point comparison of antemortem and postmortem records. Some examples of such record comparisons are dental and medical radiographic films, comparisons of fingerprints, and comparisons of nuclear DNA profiles. For a circumstantial identification to be achieved, all consistencies between the decedent and the presumptive person are noted, and no unexplained inconsistencies can exist, the greater the number of consistencies that exist, the greater the confidence in the identification. The typical decedent characterized by the Office of the Medical Examiner is an undocumented border crosser (UBC) is a Mexican National between 21 and 30 years old, three times more likely to be male, and who is only identified 73 percent of the time. This compares with close to 100 percent of identifications for deceased American citizens processed by the Office of the Medical Examiner. 10 figures, 3 tables, and 11 references