If You Think Your DNA Is Anonymous, Think Again

[...]the next logical inference is that familial searching technology and investigative techniques will eventually reach a point where investigators can identify the anonymous DNA of almost any person, even if that person's DNA is not in any public, private, government, or commercial database. The Golden State Killer A case that drew worldwide attention and kick-started law enforcement's use of familial searching in the United States involved efforts to identify a person believed to have committed over 50 rapes and at least a dozen murders in California between 1974 and 1986. Because the criminal offenses occurred in over 10 counties, news reports attributed the criminal acts to several different offenders, variously referred to as "Original Night Stalker," "East Area Rapist," "Diamond Knot Killer," "Visalia Ransacker," and "Golden State Killer. After DeAngelo's arrest, law enforcement agencies around the country rushed to apply familial search techniques in other cases to identify suspects in more than 70 murder, sexual assault, and burglary cases ranging from five decades to just a few months old.5 These cases included a truck driver in Washington State charged with the murder of a Canadian couple that occurred in 1987 and a DJ in Pennsylvania charged with the murder of a teacher that occurred in 1992.6 The Familial Search Process That Identified the GSK Suspect The principle governing familial searching is that siblings, parents, and some other relatives share features of their DNA profiles more so than unrelated individuals. Law enforcement officers arrested DeAngelo on April 24, 2018, following receipt of the laboratory report that DeAngelo and the crime scene DNA were a match.10 As this article was going to press, DeAngelo's lawyers made public pronouncements that he was willing to enter guilty pleas if prosecutors removed the death penalty from consideration.11 Other Successful Instances of Familial Searching Another well-known case involving the use of familial searching occurred following a 2008 decision by the California Attorney General authorizing familial searches of the state's felon DNA database.12 This decision led to the 2010 arrest of Lonnie Franklin for a series of offenses in the 1980s that included murder, rape, and attempted murder.