Personal Genetic Testing and the Fourth Amendment

Operating under sparse regulatory oversight, direct-to-consumer (“DTC”) genetic testing is rife with legal and bioethical issues involving data privacy, scientific accuracy, and consent. Meanwhile, despite several instances of misidentification, police have used genetic testing data to find and prosecute suspects such as the Golden State Killer (“Killer”), and are increasingly keen to access DTC companies’ massive private databases.

The Fourth Amendment’s protections against unreasonable searches and seizures would typically temper government use of individuals’ genetic material. But in justifying such searches, the government can invoke the “third-party doctrine,” which allows it to obtain data without a warrant when a suspect has voluntarily given that data to a third party. The growing popularity of DTC genetic testing and of police skill in wielding investigative genealogy ensure that many people—if not, someday soon, all people—can be identified and tracked by the government even if they themselves never complete a genetic test.

Though the Supreme Court recently revisited the third-party doctrine in Carpenter v. United States, it neither overhauled the doctrine to accommodate the vast data-gathering capabilities of modern technology, nor resolved pre-existing doctrinal confusions. Carpenter’s application to DTC genetic data is therefore unclear. This Article is among the first to examine whether third-party doctrine exempts DTC genetic data from Fourth Amendment protections. It argues that the doctrine’s premises, both before and after Carpenter, ill-fit genetic data’s hypersensitive attributes and questionable DTC industry practices. DTC DNA data thus reveals a fundamental flaw in the Court’s conception of the third-party doctrine: namely, its failure to recognize a burgeoning category of information that is generated, at least in part, by third parties, and the contents of which are not fully known to individuals when they share it. A strict warrant requirement for police searches of DTC genetic data is an essential first step for ensuring that such searches conform to the Fourth Amendment right to privacy.

The full text of this Article is available to download as a PDF.