Investigative genetic genealogy, also known as forensic genetic genealogy, is the emerging practice of utilizing genetic information from direct-to-consumer companies for identifying suspects or victims in criminal cases.[1] As of December 2023, the use of this technology has solved a total of 651 criminal cases, including 318 individual perpetrators who were brought to light.[2][3] There have also been 464 decedents identified, as well as 4 living Does.[4] The investigative power of genetic genealogy revolves around the use of publicly accessible genealogy databases such as GEDMatch and Family TreeDNA. On GEDMatch, users are able to upload their genetic data from any direct-to-consumer company in an effort to identify relatives that have tested at companies other than their own.
Identifying unknown subjects through investigative genetic genealogy is done through the use of analysis of identity-by-descent (IBD) segments of DNA that indicate shared ancestors.[5] Data available in GEDMatch, which is composed of genetic profiles from approximately 1.2 million individuals, has proven capable of identifying a third cousin or closer in over 90% of the population.[6] This information, used in tandem with demographic identifiers like age, gender, and place of residence, is sufficient for identifying any person who has a third cousin or closer within a publicly accessible genetic genealogy database.
Law enforcement agencies have leveraged the access to public databases by uploading crime-scene genealogy data and inferring relatives to potential suspects.[7][8][9] Family tree assembly and analysis of demographic identifiers is then carried out by genetic genealogy experts, either working directly for law enforcement agencies or through one of the many US companies that have been set up to work on these cases. Parabon Nanolabs is the most well known company working in this field.[10] By January 2021 Parabon claimed to have used genetic genealogy to produce an investigative lead in over 200 cases.[11] The DNA Doe Project, a non-profit organization, have also been instrumental in resolving unidentified remains cases, many of whom are victims of violent crimes.[12]