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Assignments 2 and 3 Criminalistics CMRJ 341
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I have searched in my ebook, I have googled to see if they could help me with these two questions and I can't find it or seem to word it correctly.

1. What physical and chemical properties of fibers are utilized in forensic science examinations and why? Outline the testing methods and necessary safeguards.
2. You are appointed as the lead detective with specific responsibility for fraud investigations. The fraud squad briefs you that they are preparing to raid a second hand car dealer who is suspected of fraud involving the alteration of vehicle documents, service records, mileage records and account books. What detailed instructions will you give concerning the seizure of office materials, documents and office equiptment and why ? What methods of forensic document examination would you request and what evidential strengths and limitations would you anticipate?

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Assignments 2 and 3 Criminalistics CMRJ 341
2 years ago
   Here is a start for question 1.
   There are two different categories of testing methods for physical and chemical properties of fibers.  Those two categories are non-technical which includes two different tests and technical includes two types of tests.  The two tests that make up the technical category are the feeling test and the burning tests.  The reason to do a burning test is that it can narrow down or even identify the specific fiber (Thompson & Fritchman Thompson, 2012, p. 110).  The method of a burning test is to take a small sample of the fiber and ignite it; the results will yield the answers to some questions (Thompson & Fritchman Thompson, 2012, p. 110).  The most obvious question that will be answered is does the fiber burn, and if so how does the fiber burn (Thompson & Fritchman Thompson, 2012, p. 110)?  The next question that usually receives a quick answer is if the questioned fiber radiates a smell (Thompson & Fritchman Thompson, 2012, p. 110).  Another question is if the fiber is removed from the flame source does it continue to burn (Thompson & Fritchman Thompson, 2012, p. 110)?  After the fiber is removed from the flame and or is the fiber still burning what do the remnants look like (Thompson & Fritchman Thompson, 2012, p. 110)? 
   The next non-technical test is called the feelings test.  The feelings test for fiber samples has the tester feel the sample of fiber (nitishkohli, 2009).  The person that conducts this type of test needs to be very sensitive of how the different types of textures feel like (nitishkohli, 2009).  An example of this test is to feel the difference between the feel of a wool fiber and that of a silk fiber.  The wool would be rougher in texture than the silk would be.
   In the technical test category there are the subgroups called microscopic and chemical.  The tests that are grouped under chemical tests are solubility, dye-stripping/bleaching, and differential dyeing.  The reason to conduct a solubility test is to find out if the fiber in question is soluble by several different solvents that are used (Thompson & Fritchman Thompson, 2012, p. 110).  This type of testing is usually used on paint, fibers, explosives and even drugs (Bell, Fisher, & Shaler, 2008, p. 331).  When using the solubility tests on fibers solvents such as DMF and nitro-methane are used due to those solvents belonging to the general organics group (Bell, Fisher, & Shaler, 2008, p. 331).  Solubility testing is best used for determining class characteristics because it can establish similarities between two fibers however, it cannot individualize them (Bell, Fisher, & Shaler, 2008, p. 331).
   Dye stripping and differential dye testing are similar and will be explained below.  Another type of technical testing of fibers is called dye stripping or otherwise known as bleaching.  By bleaching the fibers with different stripping solutions, the reactions of the fiber are recorded.  From the collected data, the lab may be able to identify the type of fiber and also the dye type that is used on the questioned fiber (Thompson & Fritchman Thompson, 2012, p. 110).  This type of test is done on fibers that are colored.  Differential dyeing tests are done on fibers that are white in which the sample will be treated by what is called textile identification stain (Thompson & Fritchman Thompson, 2012, p. 110).  Each textile identification stain has different results for each fiber type (Thompson & Fritchman Thompson, 2012, p. 110).
    The last type of testing under technical is the microscopic test.  The microscopic test is conducted with a microscope with a minimum magnification power of 100 (nitishkohli, 2009).  This type of test can be used on both natural and synthetic fibers (nitishkohli, 2009).  The natural fibers can be easily compared to those that are synthetic; synthetic fibers are harder to distinguish between each other because many appear to be similar to each other (nitishkohli, 2009).  One of the many precautions that are necessary is to be sure that there is enough test samples to be sure there are backups in case they are needed for repeat tests or additional tests.

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