Ever since investigators revealed that a genealogy website helped police catch one of America’s most notorious serial killers, the Golden State Killer, in 2018, genetic genealogy has taken off as a technique for solving violent crimes. Recently, for example, investigators used forensic genealogy to track down the suspect in the murders of four University of Idaho Students, Kaylee Goncalves, Madison Mogen, Xana Kernodle and Ethan Chaplin. Through genetic genealogy, investigators were able to identify Brayan Kohberger as the lead suspect after investigators successfully matched DNA evidence from the crime scene with a sample on a genealogy testing website submitted by one of Kohberger's family members.
While forensic genetic genealogy is relatively new, it is becoming increasingly common in criminal investigations due to its reliability and efficiency. However, privacy activists have criticized the practice for the mountainous privacy concerns it raises. Services like GEDMatch or FamilyTreeDNA compare autosomal DNA data files from different DNA testing companies, allowing investigators and law enforcement to compare DNA retrieved from crime scenes with samples uploaded to the databases. Although these online services allow users to ‘opt-out’ of investigative genetic genealogy matching, the majority of people who submit their data are not reading the fine print. Consequently, users miss the opportunity to ‘opt-out’ of investigative genetic genealogy matching and are automatically stuck with ‘opting in’ to the default setting which permits law enforcement to utilize and compare their DNA profile without actually obtaining their informed consent to do so.
Reasonably, privacy advocates disapprove of this automatic ‘opt-in’ setting and defend their condemnation by referencing the Fourth Amendment of the United States Constitution. The Fourth Amendment explicitly protects citizens from unreasonable searches and seizures by the government. Yet, law enforcement can use online services like GEDMatch and FamilyTreeDNA to access personal data ranging from race and eye color to familial connections and the odds of developing certain illnesses. Because the genetic information stored on these online services is far more invasive, intimate, detailed and widespread than that found in a typical police search of someone’s home, privacy advocates call for stricter federal legislation to ensure people’s Fourth Amendment rights are protected and not circumvented by the government just because these services are available to law enforcement.
Supporters of investigative genetic genealogy matching counter the privacy concerns by reminding their opponents that law enforcement participates in these databases in the same or, in some cases, more restrictive conditions than other users. Therefore, the chances that law enforcement can take advantage of these online services are unlikely since these restrictions heavily curtail law enforcement’s operations. Additionally, supporters emphasize that investigative genetic matching aims to generate investigative leads, not to convict. While this is irrefutably the intended purpose of investigative genetic genealogy matching, the reality that investigative genetic genealogy matching does lead law enforcement to the perpetrator in many cases cannot be underscored.
With genetic genealogy matching exploding as a technique for solving violent crime, balancing the benefits and harms of investigative genetic genealogy matching is increasingly important. As privacy activists have shown, there are significant, harmful and justified privacy and consent limitations to consider here. But are these considerations enough to outweigh the investigative benefits of genetic genealogy that promote public safety? The debate remains ongoing and is only expected to persist as privacy activists increasingly plead for federal policy and legislative intervention and investigators continue using genetic genealogy matching to solve violent crimes.