An Assessment of the Forensic Aspects of Genetic Genealogy

Abstract

Forensic genetic genealogy has grown in both popularity and controversy in recent years. The genetic information comes from large numbers of single nucleotide polymorphism (SNP) markers. Polymorphism variations can be traced through familial lineage, determining how closely individuals are related to each other based on the similarities and differences in SNPs within their DNA. Polymorphisms account for approximately 85% of human variation. Genealogy and ancestry determination companies trace the lineage of a person back through multiple generations using polymorphisms. As more individuals submit their DNA for analysis the genealogical profile databases continue to grow in size. Law enforcement uses genealogical determination companies to compare DNA evidence from an unknown source to the thousands of profiles readily available on such websites. Analysts can then determine possible relatives, hopefully leading to an identification of the unknown DNA samples. Companies such as GEDmatch have made identification possible. Law enforcement used the genealogy database, GEDmatch, to identify the Golden State Killer in 2018. Most of these companies explicitly stated that consumer information could only be used in limited situations by law enforcement. However, many companies allowed agencies access in additional situations, as well as subtly changed their terms and conditions to allow law enforcement increased access.