Forensic Hair Analysis Forensic hair analysis is a method of studying hair found at the scene of a crime, and the scientific study of hair is referred to Trichology. In this paper I will discuss the different techniques that are used to study hair during an investigation and the many different aspects of the hair to consider based on what type of investigation is taking place. Hair analysis can be used to determine the presence of a suspect at the scene or to detect the presence of certain chemical substances in the victim or suspect. With the help of DNA techniques used in forensic hair analysis an absolute match can be determined by examining hair found at the scene of a crime. According to Douglas Deedrick of the FBI’s
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Considering mtDNA is not as valuable as nuclear DNA, on study set out to examine the feasibility of extracting nuclear DNA from telogen hairs. According to the study, a new method was developed for qPCR which utilizes multilocus probes and permits quantitation of DNA in the picogram range. (Opel, Fleishaker, Nicklas., & Buel, 2008) Ultimately the study proved that very little DNA can be extracted from telogen hairs, and mtDNA will normally prove to be more useful for developing a profile.
Although plucked hair is typically in the anagen phase of growth allowing for both mtDNA and nDNA to be extracted from it, most hairs found at a crime scene are shed hairs and are in the telogen phase. According to one study, “The results show that a positive correlation exists between amplification success and the presence of a telogen root. Combining the amplification success with either the original or optimized protocol, telogen hairs result in an overall success rate of 77.5% compared with 65% for hairs with no roots”. (Roberts & Calloway, Mitochondrial DNA Amplification Success Rate as a Function of Hair Morphology, 2007) Another study shows the sequencing of mtDNA in shed hairs in the telogen phase can prove to be very useful in forensic hair analysis. This study points out that “routine analysis of mtDNA involves