In 2004 there was a double homicide in a Swedish town called Linköping, a small amount of DNA was found at the scene. Despite a largescale investigation, this murder would go unsolved for 16 years. In 2020 a Swedish genealogist was hired by the Swedish police and through an American commercial DNA database he was able to find the man that had gone unfound for so long. This was made possible through a change of Swedish laws in connection with the European Union’s Data Protection Regulation (GDPR), a regulation that protect the integrity of the personal data of Europeans. We have investigated how the evolution of these two legal frameworks coincides with each other, making this rather paradoxical situation possible. We have also investigated how this rather invasive technology is viewed by Swedish genealogists. These websites with their immense databases, and the technological developments in DNA technology, have changed genealogy. But they have also changed the genealogist, the foremost user of the archives today. We wanted to find out how.The investigation was conducted on three analytical levels: the legal/political, the medial and the individual level. On the legal/political level the material consists of legal texts, transcribed protocols from the Swedish Riksdag, but also two different reports on the legal status of using genetic genealogy as a method of criminal investigation. On the medial level the material consists of commercials for genealogy databases, documentaries and talk shows concerning the investigation of the murder in Linköping. On the individual level the material consists of surveys and interviews with genealogists. Follow us as we alongside police and genetic genealogists follow the bloodlines running through the archives. This is a two years master's thesis in Archival science.