Data Gathered during the Glass Examination - Essay Example

Practical Write-up about a Glass Examination Introduction / Background Information: The group of four (4) students did a Glass Examination. Each member of the group of students brought four (4) tops and each one examined the tops individually. This type of Glass Examination is usually done during forensic examination. Often, window glasses are the most fragile elements of a building or a vehicle. It is for this that bad elements in the society use the glass window in order to penetrate the premises of a building, house or vehicle that they would like to enter, rob or other purpose. Usually, in cases when thieves or criminals break these glasses, fragments of glass are projected. The projection is forward, backward, onto the perpetrator as well as into the direct surroundings. Hence, these fragments can be able to recover after the incident and examine in order to find an association between a suspect and an event. Data and Results: Table 1. Data Gathered During the Glass Examination by a Group of Four Students Student Name Observation 1st Taryn Grey stripped vest top. 54% cotton 40% polyester 3% polyamide fiber NO GLASS Grey wooly polo neck top. 38% polyester 3% Alsatian TWO PIECES OF GLASSES Green long sleeve top 100% cotton NO GLASS 2nd Heather Purple cardie pockets 75% payester 25% cotton NO GLASS Purple jumper 100% cotton NO GLASS Black vest top 95% cotton 5% elastane NO GLASS 3rd Scott jersey T-shirt 100% nylon 3 PIECES OF GLASSES Adidas T-shirt 100% polyester ONE PIECE OF GLASS Under armor 63% nylon 23% polyester 14% elastine ONE PIECE OF GLASSES THE 4rth ME Yellow T-shirt 100% cotton NO GLASS blue T-shirt 100% cotton NO GLASS Yellow T-shirt 100% cotton NO GLASS Fragments recovered from clothing are generally minute. Most of these glass fragments are easily lost from the activities of the perpetrator after the crime or offense is committed resulting to the breakage of the glass. The texture of the clothing also has something to do with the quick lost of the glass particles. In the table above, the clothing examined by Taryn, a grey wooly polo neck top which is made of 38% polyester and 3% Alsatian shows presence of two pieces of glasses. This type of cloth tend to retain glass fragments for far longer than the grey stripped vest top made up of 54% cotton, 40% polyester and 3% polyamide fiber. The same is true with the green long sleeve top made up of 100% cotton which does not show presence of glass. However, in the case of the two latter clothing, fragments can be trapped in pockets or other crevices in the clothing. It is unusual to find more than a few fragments of glass from the same source on someone's clothing purely by chance. In the clothes made of cotton, the absence of glass can be observed. Discussion and Analysis: Glass can be grouped either by substance composition or by use. The four (4) main chemical compositions of glass are soda-lime, lead, borosilicate, and special glass. Glass is composed of modifiers that are used to vary the value as well as the properties of the glass aside from silicon dioxide. Soda-lime glass is achieved by adding up soda and lime. Borosilicate glass is achieved by adding up boron oxide. During the time of burglary, theft or any criminal act, the perpetrator’s tendency is to enter by breaking s glass. During this time, some glass fragments are projected onto the perpetrator’s hair, clothing or shoes. If the perpetrator is caught within a relatively short time span after the crime is committed, the fragments of glass can still be located on the clothing, hair, clothing or shoes. At some instances, the small particles of glass can be found in the inside pockets. During investigation, the police as a rule gathers pieces of the wrecked glass as proof. These particles are brought to the investigator’s laboratory for further comparison with any glass particles found on a suspect. Glass is distinguished based on its physical and chemical qualities. During examination of the collected glass fragments, the first examination is visual glass examination. Such visual qualities being analyze are its thickness, color(s), patterns, as well as its fluorescing properties.1 2 Forensic examiners compares and contrasts with reference samples of broken glass from the scene by way of refractive index (RI) measurements.3 RI is a measure of the degree to which the glass bends light. Another test which can be conducted is the chemical analysis tests. Conclusion: The assessment process for glasses on clothing might direct to the prohibiting of a common origin between the glass from the suspect and the glass from the event scene. In the same way, it might also show that the characteristics are similar and the two samples cannot be differentiated. Therefore, supporting the hypothesis that the two samples of glass collected or gathered come from the same origin. Hence, it is important to apprehend the suspect shortly after the glass was broken. This is due to the fact that the number of glass fragments on the clothing or shoes of the suspects diminishes very quickly after the activity. Most of the glass fragments are shed from clothing within twenty-four hours. Bibliography: Caddy, B., Forensic Examination of Glass and Paint, Taylor and Francis Forensic Science Series, London, 2001. Koons, R. D., Buscaglia, J., Bottrell, M., and Miller, E.T., Forensic glass comparisons. In: Forensic Science Handbook. 2nd ed. R. Saferstein, ed. Prentice-Hall, Upper Saddle River, New Jersey, 2002, vol. 1, pp. 161-213. Petterd, C., Glass particles in the clothing of members of the public in south-eastern Australia - a survey. Forensic Science International, 1999, vol. 103, issue 3, pp. 193-198. Read More