Rootless hair as a reliable source of forensic genetic information

• NCJ Number: 311609
• Journal: Genome Biology Dated: 2026
• Author(s): Joshua D. Kapp; Ciara Wanket; Remy Nguyen; Talia Tzadikario; Hayley Neadeau; Beth Shapiro; Samuel Sacco; Camille Schwartz; Cristina Valencia; Kelly Harkins; Richard E. Green
• Date Published: February 2026
• Grant Number(s): 15PNIJ-24-GG-03843-SLFO
• Agencies: NIJ-Sponsored
• Publication Type: Research (Applied/Empirical)
• Award: Age estimation from epigenetic features of hair DNA

Abstract

The small amount of fragmented DNA present in rootless hair shafts is unsuitable for many assays, including most PCR-based assays. Thus, rootless hair DNA is often overlooked in biomedical and forensic analysis. Here we apply methods for efficient recovery and sequencing of minute quantities of short, fragmented DNA to single human hair shafts. Using this approach, we characterize DNA fragments in hair shafts. Despite the small quantities of fragmented DNA, we find multi-fold genome coverage can be generated from a few centimeters of most hair shafts – enough to generate accurate genotype calls and statistically compelling evidence for identity or non-identity.

(Publisher abstract provided.)