Elemental Composition of Hair and its Role in Forensic Identification

Hair is among most common types of evidence reported in criminal investigations. Throughout the stages of usual hair-growth parameters, hairs goes through a continuous loss from every individual, and due to this loss these hairs may be transferred from one individual to another in any criminal commotion [1]. Hair have gained a wide interest in its examination for various fields counting taxonomy, zoology, wildlife, clinical biology, dermatology and forensic investigation [2] due to its non-invasive and quick analysis along with précised and accurate results. Hair examination was in routine practice since last decades for species identification and dermatological uses but from last decade hair examination for clinical detection of various diseases [3] and for race, sex, age, and occupational identification has gained center of interest for forensic scientists/examiners [4]. Hair can be used in identification of environment exposure, food habits, soil and geographical parameters, in detection of criminal offences related to wildlife poaching of protected animals [5] and also in detection of metal poisoning [6]. In recent years mitochondrial and genomic DNA from hair has opened wide vistas for forensic investigations [7] which lead to the investigation of not only cases related to disputed paternity [8] and species identification but due to mt-DNAs hair examination has received interest of scientists in the field of evolutionary studies due to its matrilineal nature [9]. Has provides very useful information in cases of rape, sexual assaults, murder, illegal wildlife trade and so on [10]. The forensic evaluation of hair can be very important in the physical evidence examination and assessment by representing the association between the suspect flanked due to a crime scene or a victim and a suspect or representing that no evidence exists for an involvement connecting a criminal with a crime scene or a culprit with a victim [11]. Even though the science of microscopic hair investigation can never result in identification [12], the final aim of any forensic examination is to give statements on the bases of examination and scientific observations that will provide information about criminal and crime scene connection with crime in court of law or to any other agency incorporated in the investigation [13,14]. The motto of this document is to analyze the bases of microscopic hair analysis and comparison including the analysis and comparison of the morphological uniqueness present in hair. Based on this morphological uniqueness suspected hair is examined for its origin identification weather from human origin or belongs from any other species [15,16]. Within each of these two groups, further information *Corresponding author: Dahiya MS, Director, Institute of forensic science, Forensic Wildlife Biotechnology Research Laboratory, IFS GFSU, India, Tel: +9199789-11007; E-mail: [email protected]