Practical Implementation of Blood Stain Age Estimation Using Spectroscopy

Gerda J. Edelman, Martin Roos, Annabel Bolck, Maurice C. Aalders

Research output: Contribution to journalArticle*Academicpeer-review

Abstract

Blood is one of the most often encountered and valuable traces found at a crime scene. It not only contains information about what happened, but the chemical composition can also lead to the identification of the donor and even to the time of deposition, an important objective in forensic science. Many techniques have been explored for determination of the time of deposition, but none have made it into forensic practice. We have earlier used optical reflection spectroscopy for the age estimation of blood stains on white cotton, and to make this method suitable for forensic practice, we have adapted it to correct for the influence of the optical properties of the various substrates where blood may be found by extending a one-dimensional light-transport model to a two-layered model. With this model, we are able to calculate the relative amounts of OxyHemoglobin, MetHemoglobin, and Hemichrome in blood stains on colored surfaces, based on their reflectance spectra. We describe here a statistical method to calculate the 95% confidence interval around the calculated age. We demonstrate the applicability to field work and the potential value for crime investigations in a case study of a shooting incident. The absolute and relative ages of different groups of blood stains were measured using our new method. The measured age of blood stains can lead to a more realistic reconstruction of the timeline of events. To our knowledge, this paper presents the world's first implementation in practice of a method for determining the age of blood stains.
Original languageEnglish
Article number7200107
Number of pages7
JournalIEEE Journal of Selected Topics in Quantum Electronics
Volume22
Issue number3
DOIs
Publication statusPublished - 2016

Keywords

  • Biophotonics
  • biomedical equipment
  • biophysics
  • forensics
  • spectroscopy

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