Investigative Genetic Genealogy (IGG) is a powerful technique that
combines DNA analysis with traditional genealogical research to narrow down the
possibilities for the identity of an unknown individual. Since the arrest of the Golden
State Killer in May 2018, IGG has been publicly acknowledged in 464 Unidentified
Human Remains (UHR) and 318 perpetrator cases as of December 2023, and has been
used in many more unacknowledged cases. Parabon alone has contributed to over 320
identifications, more than 1/3 of which have not been acknowledged publicly. A
critical component of successful IGG is the quality of the genotypes generated from the
forensic sample. This chapter will provide a brief overview of the IGG process,
describe how data quality impacts IGG cases, and discuss various laboratory and
bioinformatics techniques for generating high-quality genome-wide Single-Nucleotide
Polymorphism (SNP) genotype data from challenging forensic DNA samples.
Keywords: Bioinformatics, DNA, Forensic genetic genealogy, Forensic genetics, Human identification, Investigative genetic genealogy, Single-nucleotide polymorphism.
