Authors
Dr. Preethi B Nayak, Dr. Ullasa Shetty
Abstract
Mass disasters and cases involving heinous crimes always pose a great challenge to the medico-legal experts. The traditional tools of personal identification methods that involve fingerprint analysis, DNA profiles, dentition and radiographs though highly effective in identification process rely on having ante-mortem records for comparison with the post-mortem data. Isotope analysis has its application in the study of ecological, geological and hydrological specimens. Isotope techniques are now being employed in forensic cases whereby investigators try to measure differences in isotopic fingerprints found within human remains. This article highlights the role of isotopes for provenancing human remains thereby resolving medico-legal cases with primary focus on teeth as a resilient specimen available. Keywords: Isotopes, Forensic analysis, Identification, Skeletal Remains, Tooth Enamel
Introduction
Police and medicolegal experts worldwide face a huge challenge in terms of identification of unknown bodies due to mounting pressure from the judicial, civil and societal bodies. Eventually such bodies are identified by comparative analysis of post-mortem data with the available antemortem data based on dental or medical radiographs, DNA profiles along with the presence of other personal identification features such as (birthmarks, surgical scars etc.)
The application of these traditional tools of identification prove to be inconclusive in cases where a victim's body is decomposed or deliberately mutilated. In such cases investigators have to rely on the missing person’s registry for possible matches. Acquiring additional information in the form of year of birth, gender along with models that predict residential patterns of inhabitants would assist forensic experts in their identification work. Age changes in teeth and bone form the basis of age estimation methods adopted by anthropologists when it comes to examination of skeletonized bodies, however these methods that predict age generally have an accuracy rate of around ±10 years, and would estimate age only at death. Aspartic acid racemization methods were thus developed that predicted age at a fairly good precision (Alkass et al., 2013).
However, the aforementioned age estimation methods being temperature dependent fail in cases of fire charred victims, also since these methods predict age at death they are of limited value in cases of burnt or mutilated bodies (Alkass et al., 2011).
Investigators thus have to look out for additional techniques (isotope analysis of human tissues- hair, nails tooth enamel) which rely on reconstructing models that will predict the life history of the deceased (based on geographic origin and socioeconomic factors) and thus aid in establishing the identity of the deceased.
Basic Principles of Isotopes
Sir Frederick Soddy coined the term isotope in the year 1913. In the periodic table all isotopes of an element occupy the same positions. The atomic number of an element is determined by the protons and electrons present in the nucleus of that particular element. The stable isotope form of any element consists of a majority of one isotope along with a minor percentage of its form e.g.: Carbon element comprises 98.89% of 12C while the remaining 1% consists of the stable isotope form of 13C (Bartelink and Chesson, 2019).
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| APA Style | Nayak, P. B., & Shetty, U. (2021). Isotopes in Teeth- A Novel Forensic Tool for Identification. Academic Journal of Anthropological Studies, 04(02), 23–27. |
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