When a crime takes place, it seems natural that collecting DNA evidence would be a necessary part of the investigation. But what happens if there isn\u2019t any DNA to collect, or DNA evidence is available but there isn\u2019t a reference to use with the evidence? Melanie Beasley, Assistant Professor of Anthropology at Purdue University, explains how the use of stable isotopes provides strong evidence to help members of law enforcement answer the question, \u201cWho was this person?\u201d Additionally, Beasley explains the field of biological anthropology which studies how humans interact with their environment.