Exploring human hair degradation: a preliminary study for estimating time-since-death.

Silva-Bessa, Angela; Ramage, Stuart; Ferreira, Maria Teresa; Dinis-Oliveira, Ricardo Jorge; Forbes, Shari L.; Dawson, Lorna

Abstract

Postmortem interval (PMI) estimation is a challenging task in forensic investigations. PMI assessment frequently requires the application of the currently available methods which can lead to unsatisfactory results due to the poor accuracy of time interval estimation. To address these concerns, the present study aimed to evaluate whether there is a correlation between human hair proteolysis and PMI. Scalp hair samples of three living donors and eleven individuals exhumed from different burial types from Portuguese cemeteries were analysed by ATR-FTIR (attenuated total reflectance – Fourier-transform infrared). Four band areas and three hair degradation indices were considered in the 2000–1000 cm−1 spectral region. When analysing the entire dataset (i.e., 126 infrared spectra) – and when separating and analysing the spectroscopic data by burial type – the ratio between amide II (∼1550 cm−1) and S = O and SO3 combined (∼1074 cm−1 and ∼1043 cm−1, respectively) suggests there is a correlation between hair proteolysis and PMI (p < 0.05). Nevertheless, it is recommended that a larger dataset is required to confirm the preliminary results obtained in this study and to explore how this correlation can be used to estimate PMI in forensic casework.

Citation

SILVA-BESSA, A., RAMAGE, S., FERREIRA, M.T., DINIS-OLIVEIRA, R.J., FORBES, S.L. and DAWSON, L. 2025. Exploring human hair degradation: a preliminary study for estimating time-since-death. International journal of legal medicine [online], Online First. Available from: https://doi.org/10.1007/s00414-025-03476-4

• Journal Article Type: Review
• Acceptance Date: Mar 18, 2025
• Online Publication Date: Mar 26, 2025
• Deposit Date: Apr 3, 2025
• Publicly Available Date: Apr 3, 2025
• Journal: International journal of legal medicine
• Print ISSN: 0937-9827
• Electronic ISSN: 1437-1596
• Publisher: Springer
• Peer Reviewed: Peer Reviewed
• DOI: https://doi.org/10.1007/s00414-025-03476-4
• Keywords: Attenuated total reflectance – fourier-transform infrared (ATR-FTIR); Microtaphonomy; Postmortem interval; Proteolysis
• Public URL: https://rgu-repository.worktribe.com/output/2782550