DNA Based Familial Searching and Related Statistical Issues

Copyright: © 2012 Ge J. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. DNA databases have become essential tools for forensic investigations. The typical DNA database search seeks direct matches between a forensic profile from crime scene evidence and an offender profile in the database. However, direct matches may not be obtained because the database does not contain all people in the population. As of January 2012, there are about 10.5 million offender profiles in the US National DNA Index (NDIS) [1], which only covers about 3% of the US population (i.e., there are more than 313 million people in the US [2]). To extend the investigative lead value of current databases, an additional approach, familial searching, has been used to determine the source of a forensic sample by searching the database for possible relatives (e.g., parents, children, full-sibs) of the true source of the sample. It also is an effective way to expand the utility of DNA databases with relatively low costs. This approach, when performed under stringent criteria, has been used to develop strong investigative leads and to successfully identify perpetrators of crimes [3-5].