Week 1 Hair and Fiber Analysis PDF

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Comprehensive and thorough assignment detailing criminal justice local, state, and federal procedures involving investigate methodologies for crime prevention and future advancements....

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Hair & Fiber

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Week 1 Assignment: Hair and Fiber Analysis Terralyn Franklin CRJ Professor Lofland University of Arizona Global Campus

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Hair Evidence: Biological Hair evidence is a notorious piece of evidence that is used to make connections of a crime and/or scene, between suspect and victim, and more. Primarily there is a very detailed methodology for handling hair evidence using scientific techniques both on a crime scene and in a laboratory. These techniques range from collection of samples, microscopy, and DNA analysis. Frequently, hair is obtained from the crime location and utilized as contributing biological proof for a crime. This can be useful in deciding the suspect of wrongdoing and in giving more data about what actually occurred. When assembling a hair test, it is smarter to have a bigger example of hair instead of a more minute sample, as various hairs on a similar individual can contain numerous varieties. The normal hair test submitted as proof ranges somewhere between the range of 24 to 50 pieces (Deedrick, 2004). There are different approaches to gathering a sample of hair that can be utilized as proof. An examiner can gather hairs they notice outwardly (with tweezers or by hand), and they can likewise utilize clear tape to lift non-apparent hair from an assortment of surfaces, like attire and/or clothing. Different strategies for hair test assortment incorporate brushing and cutting techniques. Furthermore, there is a very detailed approach to handling these samples in a laboratory using both the microscopy and DNA analysis methodologies (Deedrick, 2004). In a laboratory, a correlation and/or comparison microscope, which is composed of two compound light magnifying instruments associated by an optical extension. This permits the analyst to see a familiar and unfamiliar hair test at the same time. The multi-stage assessment measure begins with the investigator setting up whether the obscure hair is of a creature or

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human being. In the event that it is an animal hair, the investigator can additionally recognize it as having a place with a specific animal genus group. Animal hairs found on different pieces of evidence can connect a suspect to a crime location, a vehicle, and/or area where the victim may have been. Hairs from a pet the suspect possesses, for instance, may likewise be moved to the casualty when a speculation connects. On the off chance that the hair is linked to a human being, examination can assist with recognizing people dependent on the course of action, appearance and dissemination of specific qualities inside various districts of the hair (Deedrick, 2000). Furthermore, an analyst has more work to do once the observation and determination of the sample is depicted. Forensic scientists then have to test the suitability of the sample for DNA analysis. To test the reasonableness of a human hair sample for nuclear DNA examination, hair microscopy is the common method used for observation. Microscopy is utilized to see the finish of a hair and determine whether it contains a root. If proven that this is true, the example can be tested utilizing a nuclear DNA testing methodology called Short Tandem Repeat (STR) examination (Deedrick, 2000). A hair that has been shed without a root can't be sent for this sort of testing, however a sample can in any case be exposed to mitochondrial DNA (mtDNA) testing of the hair shaft.

Fiber Evidence: Non-biological Connecting a suspect to the location of a crime is a significant component in forensics & criminal examination. This can be accomplished through the area of material fibers like those from the victim’s clothes or the crime location on the attire of the suspect. Also, this can be achieved through the determination of fibers like those in the subject's clothing at the location of

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the crime. A fiber is the smallest unit of a material that has a length ordinarily more prominent than its width. Fibers can develop naturally as plant and animal strands, however they can be manmade as well (i.e. clothing and other cloth materials). Textile and/or material fibers can be transferred between two people, an individual and an item, and between two articles. At the point when fibers are coordinated with a particular source (i.e. the victim’s fabric, suspect, and the crime scene), a worth is set on that affiliation (Hansen, 2007). This value is reliant upon numerous variables, including the sort of fiber discovered, the color & shading of the fiber, the quantity of strands discovered, the area of fibers at the crime location or on the person in question, and the quantity of various fibers at the crime location or on the victim that match the apparel of the suspect (Hansen, 2007). Fibers are collected from a crime location utilizing tweezers, tape, and/or a vacuum instrument. The most widely recognized source of transferable fibers are clothing, wraps, mats, furniture, and covers. By coordinating with strands at the location of a crime to connect things to a suspect, analysts can place individuals at a crime location. Primary analysis techniques incorporate individual fiber assortment utilizing tweezers or vacuuming a region and arranging the materials at the research facility. Strands or items containing fiber evidence ought to be air dried prior to putting in fixed compartments (Hansen, 2007). Natural stains debase with time. This interaction is sped up when things are wet and fixed in hermetically sealed compartments. Try not to bundle things on a surface without first altogether cleaning that surface. The most widely recognized utilization of fiber investigation is tiny assessment of both longitudinal and cross sectional examples (Deedrick, 2000). While this is the most widely

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recognized strategy for undertaking fiber examination, others do exist. These incorporate the consuming and dissolvability techniques. Forensic and crime scene analysis investigators frequently have just simple strands to work with. From these strands, fiber testing is finished utilizing powerful examination magnifying instruments to analyze surface and wear next to each other appraisal. Compound examination can decide the substance arrangement of the fibers. This technique is widely used with fiber evidence to effectively and thoroughly make connections within a crime scene (Hansen, 2007). Both hair and fiber evidence has evolved over time. With advancement and aging increase of technology and other essential instruments for both evidences, these factors are both are huge contributions to forensic science.

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References Deedrick, D. W., & Koch, S. L. (2004). Microscopy of hair part 1: a practical guide and manual for human

hairs. Forensic science communications, 6(1).

Moeller, M. R., Fey, P., & Sachs, H. (1993). Hair analysis as evidence in forensic cases. Forensic science international, 63(1-3), 43-53.

Deedrick, D. W. (2000). Hairs, fibers, crime, and evidence: Part 2, fiber evidence. US Department of Justice, Federal Bureau of Investigation. Hansen, N., Klein, T., Magerl, W., & Treede, R. D. (2007). Psychophysical evidence for longterm potentiation of C-fiber and Aδ-fiber pathways in humans by analysis of pain descriptors. Journal of neurophysiology, 97(3), 2559-2563....