This study evaluates the effectiveness of generating Single Nucleotide Polymorphism (SNP) profiles from rootless hair samples for application in Forensic Investigative Genetic Genealogy (FIGG). The research examined the consistency and reliability of SNP data produced from hair samples of different ages and storage conditions. Hair strands stored at room temperature for 47 years were compared with newly collected hairs originating from the same donor. In addition, hairs and nails recovered from cadavers donated to the Australian Facility for Taphonomic Experimental Research (AFTER) and buried for seven years were assessed against buccal swabs taken at the time of donation.

DNA extraction and SNP genotyping were performed by a US-based service provider, and the resulting profiles were uploaded to a publicly available FIGG database to evaluate upload suitability and matching outcomes.

Analyses focused on detecting notable differences in SNP profile quality between aged and recent samples and determining how these differences influenced database upload success and match list generation. The findings suggest that SNP profiles from aged and buried hair samples were generally concordant to those from fresh material. However variation in match lists was observed in terms of the order and composition, which could potentially impact the genealogical research. These differences are important for FIGG practitioners to consider when working with similar sample types.

Taken together, these results demonstrate that rootless hairs of considerable age and environmental exposure can produce SNP profiles suitable for FIGG, provided that practitioners account for expected variability in match lists. Verifying emerging workflows and external service providers using known donor material offers a powerful pathway to strengthen FIGG capability. This approach not only builds confidence in casework readiness but also supports the development of rigorous, defensible genetic genealogy practices within the field.

Authors

• Jennifer Raymond (Forensic Evidence and Technical Services, New South Wales Police Force, Australia)
• Nathan Scudder (Australian Federal Police, Australia)
• Dadna Hartman (Victorian Institute of Forensic Medicine & Monash University, Australia)
• Runa Daniel (Victorian Institute of Forensic Medicine, Australia)
• Alison Sears (Forensic Evidence and Technical Services, New South Wales Police Force, Australia)