Commercial DNA databases and criminal investigations: Why the customer should not be king

By Nina de Groot

In a colorful envelop, tens of millions of people around the world have sent their cheek swabs to a commercial company with the same colors on its facade. By taking a DNA test, they hope to find out about long-lost relatives, their genetic susceptibility for breast cancer, athletic performance capabilities, or – just in case you cannot find a mirror – a unibrow. But the 90-dollar DNA testing kits can also be helpful in quite another way: the identification of criminal suspects. By uploading a DNA sample, retrieved from a crime scene, to a genetic genealogy database (the website GEDmatch or the direct-to-consumer database FamilyTreeDNA), one can identify distant relatives of the unknown perpetrator. Through this relative, the intersections of both family trees can be investigated and one can eventually zero in on the suspect. Because the colorful DNA tests establish such an extensive DNA profile, it is possible to identify even very distant genetic relations, such as relatives who share their great-great-great-grandparents with the unknown perpetrator.

Obviously, this technique can be very useful to identify perpetrators of horrendous crimes. Indeed, this so-called investigative genetic genealogy (IGG) has already been used in hundreds of criminal investigations and multiple cold cases have been solved. Issues concerning IGG often revolve around questions such as: did the customer really give valid consent for use in criminal investigations? Has the database given complete information about possible forensic use? Is the raw genetic data of customers sufficiently protected so that police cannot see any sensitive information? Those are all very relevant questions to consider, but what if they were – perhaps in some utopian future or, as some say, already now – all answered with ‘yes’? What if a customer whole-heartedly and fully-informed consented to use her DNA sample for forensic use and her privacy is tremendously well protected? Would there still be a problem? Yes, we argue, in a new Feature Article in the Journal of Medical Ethics.

Although questions around privacy and informed consent are important, there is a risk they will  distract from more fundamental issues. In our paper ‘Commercial DNA tests and police investigations: a broad bioethical perspective’, we aim to broaden the ethical perspective beyond the individual customer. Because of the ability to identify very distant relatives, if only around two percent of a population were in a DNA database accessible by law enforcement, almost everyone in that population can be identified. Therefore, a mere focus on privacy and decision-making of the individual will be insufficient to grasp the full ethical complexities of IGG. We discuss several ethical issues that go beyond the individual, including the collective, international, transgenerational, and commercial dimensions of IGG and discuss why the customer should not be King.

The future use of this novel technique with consequences on a societal, legal, criminal, political, and ethical level, should not be left simply to the judgement of individual customers or the self-imposed ethical reflection of billion-dollar companies. There is an urgent need for governance that does not depart solely from the individual, but recognizes IGG as it – perhaps primarily – is: a collective issue that affects, first of all, the many instead of the few.


Paper title:
Commercial DNA tests and police investigations: a broad bioethical perspective [Open Access]

Authors: Nina F de Groot, Britta C van Beers, Gerben Meynen

Affiliations: VU University Amsterdam, Department of Philosophy

Competing interests: None

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