Skip to main content
eScholarship
Open Access Publications from the University of California

UC Davis

UC Davis Previously Published Works bannerUC Davis

Forensic determination of hair deposition time in crime scenes using electron paramagnetic resonance.

  • Author(s): Shankar, Nikhita;
  • Guimarães, André O;
  • Napoli, Eleonora;
  • Giulivi, Cecilia
  • et al.

Published Web Location

https://onlinelibrary.wiley.com/doi/epdf/10.1111/1556-4029.14570
No data is associated with this publication.
Abstract

Several types of biological samples, including hair strands, are found at crime scenes. Apart from the identification of the value and the contributor of the probative evidence, it is important to prove that the time of shedding of hair belonging to a suspect or victim matches the crime window. To this end, to estimate the ex vivo aging of hair, we evaluated time-dependent changes in melanin-derived free radicals in blond, brown, and black hairs by using electron paramagnetic resonance spectroscopy (EPR). Hair strands aged under controlled conditions (humidity 40%, temperature 20-22°C, indirect light, with 12/12 hour of light/darkness cycles) showed a time-dependent decay of melanin-derived radicals. The half-life of eumelanin-derived radicals in hair under our experimental settings was estimated at 22 ± 2 days whereas that of pheomelanin was about 2 days suggesting better stabilization of unpaired electrons by eumelanin. Taken together, this study provides a reference for future forensic studies on determination of degradation of shed hair in a crime scene by following eumelanin radicals by utilizing the non-invasive, non-destructive, and highly specific EPR technique.

Many UC-authored scholarly publications are freely available on this site because of the UC's open access policies. Let us know how this access is important for you.

Item not freely available? Link broken?
Report a problem accessing this item