Investigative genetic genealogy in Europe: Why the “manifestly made public by the data subject” legal basis should be avoided

Investigative genetic genealogy has emerged as an effective investigation tool in the last few years, gaining popularity, especially after the arrest of the Golden State Killer. Since then, hundreds of cases have been reported to be solved thanks to this novel and promising technique. Unsurprisingly, this success also led law enforcement authorities in the EU to experiment with it. However, there is an ambiguity on which legal basis in the EU data protection framework should be used to access the personal data of genetic genealogy database users for investigative purposes, which may put the legality and legitimacy of investigative genetic genealogy in Europe at stake. Accordingly, this article examines whether the “manifestly made public by the data subject” legal basis enshrined in Article 10(c) of the Law Enforcement Directive could be used for such purposes. Based on its analysis, the article argues that this legal basis cannot be used for such purposes, given that the personal data in question are not “manifestly made” “public”, and they are not disclosed “by the data subject” in all cases. Therefore, the article concludes by suggesting a way forward to ensure the lawfulness of this investigation method in the EU data protection framework.