Forensic Hair in Crime Scene Investigation - Research Paper Example

Forensic Hair in Crime Scene Investigation Abstract: Generally 100 hairs are lost daily by individuals, which increase the chances of the presence of hair at various places. Found at the crime locations, these hairs can be used as samples to investigate the crime suspects by comparing the samples with the samples of the suspects. Also, the nature and intensity of the crime and violence at the crime scene can be predicted using the hair samples. The human hair has certain properties which are specific to certain people, thus using procedures like chemical analysis of DNA various conclusions can be derived. However, the results sometimes may not be as accurate and if the hair has been treated by chemicals, the results might be different. Nevertheless, hair analysis can still be an important procedure used for suspecting crimes if used with other similar procedures. Hair is often found at crime scenes and thus, can be used for forensic analysis to reveal important information about the suspect as well as the victim. Since it is very common for humans to shed about 100 hairs daily, it is highly likely that the hair will be found at crime scenes relevant to homicides, assaults, even burglaries and theft related crimes. Hair analysis is usually of three kinds, i.e. chemical assays, DNA analysis and the microscopic analysis of the hair to reveal important information about the person the hair belongs to. Moreover, this analysis can be used in a variety of ways to investigate the crime scenes, which will be discussed in this paper. However, there are some issues associated with the forensic hair analysis which will also be addressed in the paper. Trichology is the scientific term used for the study of hair and the procedures regarding hair analysis that have been used for forensic studies for many years. Thus, hair has always been an important part of the crime investigation process, whereby practices have evolved and modernized over the years. Earlier, chemical analysis was the most prominent technique being used to match various samples, however with the modernized DNA techniques, details about the owner of the hair can be revealed (Kintz p. 76). There are, however, three different kinds of forensic hair analysis each of which holds significance for the purpose it offers. The first type involves chemical assays, which is usually used to analyze drug suspects since it offers a test for the metals detection in the body. The second kind of the test, and the most popular one, is the DNA testing where the roots of the hair are taken as a sample to analyze the details (Robertson p. 99). Moreover microscopic analysis is yet another technique which is used for comparing and contrasting samples, proficiently being used for crime scene investigations. According to the forensic experts, longer hairs are more suitable for crime scene investigations as they reveal the most of the information about the owner. However, along with the length of the hair, the kinds of hairs are also important, which may be the head hair, the hair on the eye brows, the ones on the eye lashes, beard or the moustache hair, the body hair and lastly the public hair. Also, in this case, prior to analyzing the hair, it needs to be understood that the hair goes through different cycles of growth and while analyzing the level needs to be kept in mind. The growth phase comes first which lasts almost 1000 days, while the telogen phase follows where hairs fall and it lasts about 100 days, while the transition phase is somewhere in between. About 80-90% of the hairs are the ones still growing, however it is very difficult to determine the pattern. Moreover, the material from the body is also often transferred to hair and for this, about a spoonful of hair from the nape of one`s neck is taken as a sample to analyze which material was present in the body (Lee p. 7). Once an analysis has been carried out, there are many ways how it can be connected with the crime investigation. Firstly, the hair which has been found at the crime scene determines important information about the person who owned the hair, i.e. the species, the location from where the hair would have originated, the reason why the hair was lost, the age of the person, his race, any kinds of chemical treatments to the hair etc which can be helpful in identifying the relevant suspect. Moreover, the cultural orientation of the person can also be traced, as Europeans are found to have straight hair, Asian to have curly hair, while Africans to have frizzy hair with a thick texture. Moreover, the follicle of the hair is found to have chromosomes which help the analysts to conducts DNA tests which even have the capacity to identify the sex of the person (Kobilinsky p. 20). The nature of the crime or in other words the intensity of violence during the crime can be analyzed, for instance if the hair was still at its telogen phase, it signals violence. Similarly, any burn or cut can also be indentified further clarifying the nature of crime. However, whereas on the one hand hair analysis is an ideal technique which can be used to find out the suspect, on the other hand, many different issues have also been suspected with this technique. The standard of the analysis must be very high and the lab conducting the tests must be authentic, as there have been cases where the reports turned out to be faulty. Sometimes, when tests are conducted on sub-samples, the reports might turn out to be different than the original. Also, in case of chemical analysis, sometimes when second hand drugs are used the results might be distorted to a great extent. Pollution also, in some cases, may affect the analysis reports as other substances get mixed up with the already present ones to yield different results. Some people use various other chemicals on their hair including hair-dye, shampoo, hair sprays, hair serums, hair conditioners or other similar products. This changes the original texture and nature of the hair, again distorting the results to a great extent. Also, the hair should be analyzed right after the crime scene investigation, as a delay of a few days can further distort the results (Bohan and Heels p. 45). However, the issue is resolved by comparing the results determined by the hair analysis with other reports, i.e. urine tests for instance, to confirm the presence of drugs in the body, or even blood tests in other cases (Mieczkowski and Lersch p. 2). Similarly, other results obtained from hair analysis can be compared with tests including the finger prints analysis or other similar tests to compile a complete test report so that any errors can be minimized (Edward p. 19). Thus, in any case, whether taken as a supplementary or rather a complementary test, hair analysis is a very important test used for crime investigation. In conclusion, every person loses about 100 hairs each day, also animals lose many hairs due to which these hairs are mobilized and found at different locations. For this reason, chances are that hair may be found at crime locations which can be analyzed in different ways to reach suspects or even to identify the victims. There are many different ways by which the forensic hair analysis can be carried out, for instance, by chemical analysis where the metals capacity can be computed, similarly via DNA testing where complete analysis of the DNA can be done and microscopic analysis where results can be compared and contrasted. These results are used to reveal many features of the owner of the hair, including the sex of the person, the race, ethnic background, color and other similar features (Butler p. 10). Also, in another case the hair also indicates how the crime took place and what the nature of the violence was. However, due to some of the factors, it may become difficult to confirm the authenticity of the results. Firstly, the sub samples may give different results than the original sample. Similarly, external factors like pollution and chemicals etc can alter the results to a great extent. But, to get the most accurate results, the triangulation technique can be used, which implies that other forensic procedures can be used in addition to the hair analysis to get the most accurate results. References: Bohan, T. L. and Heels, E.J.(1995). The case against Daubert: New Scientific Evidence "Standard" and the Standards of Several States. Journal of Forensic Sciences. 40,1030- 1044. Butler, J. M., & Butler, J. M. (2010). Fundamentals of forensic DNA typing. Amsterdam: Academic Press/Elsevier. Edward J. Imwinkelried (1982) Forensic hair analysis: the case against the underemployment of scientific evidence, 39 Wash. & Lee L. Rev. 41 http://scholarlycommons.law.wlu.edu/wlulr/vol39/iss1/5 Kintz, P. (1996). Drug testing in hair. Boca Raton, FL: CRC Press. Kobilinsky, L. (2004). DNA: Forensic and Legal Applications. Wiley. Lee, G. D. (2007). Practical criminal evidence. Upper Saddle River, N.J: Pearson Prentice Hall. Mieczkowski , T. & Lersch K. M.T, (2002) "Drug-testing police officers and police recruits: The outcome of urinalysis and hair analysis compared", Policing: An International Journal of Police Strategies & Management, Vol. 25 Iss: 3, pp.581 – 601. Robertson, J. (1999). Forensic examination of hair. London: Taylor & Francis. Read More