New genetic sleuthing tool: Forensic genealogy

Abstract

Recently, a new genetic sleuthing tool, forensic genealogy, was used to track down Joseph James DeAngelo suspected of being the "golden state killer" in the US. Since then, decades-old cold cases and some fresh crimes have been solved after genetic genealogy searches. While the description of the genomic analysis steps taken to find DeAngelo appeared to be the latest groundbreaking technology, investigators found genetic relatives could link even distant relatives accurately by locating identity-by-descent (IBD) segments after querying direct-to-customer (DTC) genomic database. In addition, in order to solve those cases, powerful triangulation techniques combined with some traditional genealogical methods in forensic genealogy were used to identify shared segments for validating the links, and the details were introduced. Forensic genealogy is the study of identification and kinship in legal contexts including finding family references for DNA identification, identifying missing persons, locating heirs for probate matters and more. The advantages for the forensic genetics community of introducing the new technology were discussed. Such as, improving the effectiveness of the existing DNA database to identify suspects in crime, reducing the impact of "innocent" individuals due to the investigation and protect security of case information, and possessing higher success rates than with surname inference from the Y chromosome. Also, the ethical issues and risks of false identification should be taken into account. Legal and privacy experts worry that genetic genealogy searchers will put numerous people under police scrutiny and will never guarantee total privacy of their DNA information. Although the detailed linking information available in a DTC genealogy database is private to those directly concerned, which is guaranteed by the companies, they also warn that legal processes may force them to reveal personal information. Meanwhile, using this approach to uncover relatives may not be that simple if the relationship is more distant, the number of familial relationships increases exponentially witha number of generations, and only a small proportion of them will be available on any given DNA database. There remain implementation issues that would need to be debated by the public and ultimately resolved by government. First of all, to make laws to strictly control access to genomic data for privacy protection of relevant personnel. Secondly, to avoid using phenotypic markers, such as the markers in relation to hair color, stature and different human diseases, in creating the DNA database. Thirdly, to normalize the formulas and parameters for linking distant relatives to prevent mismatches caused by subjective misjudgments of forensic genealogists. Finally, to apply the technology as an auxiliary tool for other identification methods at present, due to its complexity. Even though the use of forensic genealogy will bring many ethical issues and risks of miscalculation, it is not the reason to abandon the application of this new technology. More standards and policies should be put in place.