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

Area of Science:

• Forensic Science
• Biochemistry
• Spectroscopy

Background:

• Estimating postmortem interval (PMI) is crucial in forensic investigations but current methods lack accuracy.
• Existing PMI estimation techniques often yield unsatisfactory results due to poor time interval accuracy.

Purpose of the Study:

• To investigate the potential correlation between human hair proteolysis and postmortem interval (PMI).
• To explore a novel approach for improving PMI estimation accuracy in forensic casework.

Main Methods:

• Analysis of scalp hair samples from living donors and exhumed individuals using Attenuated Total Reflectance-Fourier-Transform Infrared (ATR-FTIR) spectroscopy.
• Evaluation of four band areas and three hair degradation indices within the 2000-1000 cm⁻¹ spectral region.
• Statistical analysis of infrared spectra, considering the entire dataset and data stratified by burial type.

Main Results:

• A significant correlation (p < 0.05) was observed between hair proteolysis and PMI.
• The ratio of amide II to S=O and SO₃ combined spectral bands indicated this correlation.
• Preliminary results suggest hair proteolysis as a potential biomarker for PMI.

Conclusions:

• Hair proteolysis shows a promising correlation with postmortem interval (PMI).
• Further research with a larger dataset is recommended to validate these findings.
• This correlation could potentially be developed into a reliable method for PMI estimation in forensic investigations.