The Case of the Golden State Killer: The Wider Implications of Your Consent for Genetic Testing
Last week the state of California arrested a man linked to serial murder and rape in the 1970s and 1980s due to DNA evidence. While using DNA in criminal investigations is not necessarily new, this case is unique in that the DNA of a distant relative of the suspect was voluntarily uploaded to a database, leading to the arrest. This arrest has influenced the debate about privacy and ethical issues surrounding genetic information.
In genetic counseling appointments, we discuss how your genetic information doesn’t only belong to you, but also to your biological relatives. We talk about this in the context of if a person is identified as having a genetic condition, there are likely going to be implications for their family members as well. An entire family does not consent to one person having genetic testing, but the consent of one person can uncover genetic concerns for multiple people. Consent for genetic testing on one person can also reveal the identity of a criminal, as in the case of the Golden State Killer.
There are many articles that go into detail about this case, but essentially the Golden State Killer committed 12 murders and over 50 rapes in California in the 1970s and 1980s. Investigators collected DNA from the crime scenes, but technology at the time did not allow for much to be done with that evidence. Recently, investigators uploaded the crime scene DNA to a public database called GEDmatch. The intended purpose of GEDmatch is to connect long lost family members and build your family tree by uploading your DNA sequence that you obtained elsewhere, like by using 23andMe. So when the suspect’s DNA was uploaded to the system, there was a match to a distant family member who had also uploaded his/her genetic information.
On average, a person shares 50% of their unique DNA sequence with each of their parents, full siblings, and children. They share 25% with their grandparents, aunts, uncles, nieces, nephews, and half-siblings. They share 12.5% with first cousins and great-grandparents, and the pattern continues to further distant relatives. When DNA testing shows a percentage match between two people, it cannot necessarily tell you how they are related, but it can tell you a few places to look on the family tree.
A DNA sequence does not inherently disclose someone’s identity. Nowhere in my billions of base pairs can you find my social security number, name, or address. But when one person takes ownership of their DNA sequence and it is determined that a DNA sequence definitively belongs to this person, everything changes. Databases connecting DNA sequences and human identities have been growing mainly through criminal cases, but in recent years the popularity of at-home genetic testing with 23andMe and Ancestry.com DNA testing have to lead to millions of people sequencing their DNA and taking ownership of that sequence. In the past several days the big players in the industry have come out stating that they do not share your personal information with law enforcement, but may be required to comply in cases where there are warrants or subpoenas.
Most direct to consumer DNA testing companies allow consumers to download a file containing their sequencing information, and once this is handed over, the individual is responsible for the privacy of their data. In this story, the individual had downloaded their information from a testing company and uploaded it to a public database, so no subpoena was needed to make the connection. What does make some people following this story uncomfortable is the fact that the investigators created a fake profile when uploading the killer’s DNA to GEDmatch. The investigators would have had to check a box stating that the DNA belonged to themselves, someone for whom they were the legal guardian of, or that they had “obtained authorization” to upload the sample on the owner’s behalf. Of course, that was not this case.
Like most stories and debates about genetic information and privacy, there are a lot of questions, a lot of opinions, and few answers. I suspect there will come a time when having our DNA sequence known and connected to our identity is inevitable, but we are not there yet. Until then, we each can make a conscious decision about our genetic information, making it be known and public, known and private, or not known at all. As a genetic counselor, I do my best to help people consider all the possible implications of genetic testing before sending in their sample. This list had included things like unexpected genetic diseases, learning your dad is not your biological father, or finding out parents are actually related. But I guess now my consenting spiel will also have to include the possibility of finding your cousin’s criminal past. I wonder what I’ll add to the list next?
Erin O’Toole, MS, CGC received her Master of Science in Medical and Molecular Genetics from the Indiana University School of Medicine and is certified by the American Board of Genetic Counseling. As owner of Family Forecast, Erin meets with clients across the country and helps families understand their genetic risks and test results via telemedicine. For more information or to schedule an appointment visit www.family-forecast.com.
