Familial DNA searching (FS) is an additional search of a law enforcement DNA database when the initial search found no direct match of the DNA of unknown origin to the DNA of an individual in the database. A subsequent FS is a two-phase process that involves identifying individuals in the DNA database whose DNA indicates they are close biological relatives of the unknown person with the DNA of interest. FS is based on the concept that first-order relatives, such as a sibling or parent/offspring, often will have more alleles of their DNA profiles in common than those of unrelated individuals. The first phase of FS produces a candidate list from the DNA database ranked by likelihood ratio estimates supporting the specified relationship compared with the alternative hypothesis of being unrelated. The second phase of the process typically uses additional genetic testing to confirm or refute the potential relatedness. In States that allow FS, its use has brought several investigations to successful conclusions and jury-trial convictions. Opponents of FS, including the American Civil Liberties Union, are concerned that searching for suspects among the DNA profiles of relatives in a criminal DNA database is an invasion of privacy and violates the fourth amendment by arbitrarily creating two classes of people, i.e., relatives of convicted persons, who are subject to FS, and other people who are not. Pro and con arguments for FS are discussed in the webinar series.