Forensics Fiber Analysis as a Significant Aspect in Convicting Offenders - Coursework Example

Fiber Analysis Forensics Introduction Fiber analysis is a fundamental element in conducting forensics where the crime scene investigators use it to place a suspect at the site of the crime, or proving that a suspect had prior contact with the victim (Yount, 2006). Fibers are transferred from one point to another upon contact thus its significance in tracing back to the assailant (Lee & Harris, 2000). Forensic evidence has over and again used fiber evidence by crime detectives and prosecutors to prove offender’s guilt, thus, putting many offenders behind bars (Geberth, 2006). However, the art of fiber analysis and its usage in court is dependent on other evidence like hair, blood, nail, footprints among others. This is because; it is hard to connect the fiber at a crime scene to a particular suspect, owing to the numerous fibers manufactured (Dunbar & Murphy, 2009). Fibers are nominal components of a fabric, whose measurement lengthwise is more than its width. Fibers twirled together forms yarns. As a form of forensic evidence, fiber transfer is dependent on various elements. This includes; the kind of fiber in the fabric, the measurement lengthwise of the fabric, the technique used to spun the fiber into fabrics, and the method of making the fabric material (Yount, 2006). This report seeks to highlight the forensic fiber evaluation, evaluate the different types of fiber, the features of different fibers, and the concept of fiber transfer. Moreover, evaluate the usefulness of each item collected in the case, persistence, recovery and the different analysis techniques used to analyze fibers evidence, and advantages or disadvantages with any such systems. The Payne Case The case which highlight the use of fiber analysis as evidence used to convict Roy Whiting of the murder of an 8 yr old Sarah Payne. Whiting was among the initial suspects owing to his prior conviction of sexual offence. Although Whiting denied charges brought against him, fibers on the Velcro fastener on Payne’s shoes and a single hair would prove useful in bringing Whiting to trial and putting him in Prison for 50 years. Fibers found on Payne’s shoes matched fibers on a red sweatshirt that belonged to Whiting. Moreover, fibers further collected from the suspects van, fibers on Payne’s hair and DNA testing confirmed that a single hair on Whiting’s sweatshirt belonged to Payne. In this case, substantial amount of items were used for analysis. Since fiber analysis was not sufficient evidence, experts including pathologists, entomologist, a geologist, an archaeologist, lubricant experts and profilers were called in to support the evidence gathered (Innes, 2003). Since Payne’s body had badly decomposed, a DNA test of her body muscle and a tooth were used to verify her identity. Contents from Whiting’s van, which included a petrol receipt, indicated he had been in the vicinity from where Payne’s body was recovered. The fact that new fabric had been placed on the seats, and refurnishing of the van done, it pointed towards Whiting as the most probable suspect. Fiber analysis helped to match Payne’s shoe to her school shirt to verify that the shoe was really hers. Forensic of fiber analysis There are two forms of fibers. There are natural fibers and synthetic fibers. Natural fibers are from animals and plants like wool and cotton respectively, while synthetic fibers are processed, and made from polymers (Geberth, 2006). Synthetic fibers include rayon, polyester, Nylon, Acrylics among others. Natural and synthetic fibers are span to make fabrics (Lewis & Sigman, 2007). When conducting a fiber forensic analysis, the analyst looks at the cross section of the fiber, since majority of fibers are producer- specific. Cross section of fibers may differ in their shapes, size and length. This is integral in performing fiber connection of what was at the crime scene and that found with the suspect (Geberth, 2006). Fibers are analyzed under a microscope to identify similarity of cross sectional shapes, identifying the color and folds of the fiber, its span, fiber’s gleam, any evident damage and the width of the fiber (Innes, 2003). The color and dyes can be analyzed by using chromatographer, which break up the chemical components of the dye or color in the fiber (Lee & Harris, 2000). An analyst pays greater attention to the method used to spread the color on the fabric, and the way the fabric absorbed it during production. The loss of color on the fiber is fundamental in connecting two fibers collected at different places (Geberth, 2006). It is important to note that the amount of fiber and location of the fiber registers the probability of the suspect having had contact with the victim. During a microscopic analysis of fiber, an analyst can use compound microscopes, phase contrast microscopes, either comparison microscopes or electron microscopes (Lewis & Sigman, 2007). Additionally, he can use spectrometers and micro-spectrophotometer, which spilt light in the fiber and indicates how the light interrelates with the fiber respectively. Using the Locard’s concept, it suggests that any contact between individuals leaves a clue, which can be used to trace back to them (Geberth, 2006). These traces are either from the offender leaving behind something that belongs to them or carrying with or without knowledge something that belongs to the victim (Lewis & Sigman, 2007). Therefore, forensic analysts in Payne’s case had it easier considering the numbers of suspects were narrowed down to one person. Therefore, it was easier to do a fiber association between fibers found on the shoes and Payne’s hair and matching it to Whiting’s sweatshirt, her own school sweatshirt and other items, which were critical in performing fiber analysis (Innes, 2003). The evidential value of each item, fiber transfer, persistence and recovery There were primary and secondary fiber transfers in Payne’s case. Primary transfers collected on Payne’s shoes, which matched fibers on Whiting’s sweatshirt, and fibers speculated to be Payne’s dress matched those found on Whiting’s sweatshirt. Her shoes also matched fibers on her school shirt. Secondary fiber transfer was fiber of the clown curtains on Payne’s shoes which belonged to Whiting (Innes, 2003). The shoes were critical to identifying the first clues to the killer, since they contained fibers from the red sweatshirt, the curtain, the passenger seat, Payne’s blue dress and Payne’s school shirt. A curtain was collected from Whiting’s van, whose fibers matched with fibers on Payne’s shoes; this was because of one fiber from the curtain, had several colors just as the curtain in Whiting’s van. Additionally, there were fibers on Payne’s hair which when analyzed matched with the suspect’s sweatshirt; it matched with a fiber on the van’s seat and his socks. There were blue fibers found in Whiting’s home, which matched the description of the clothes the victim had on the day she disappeared. An analysis of fibers from a similar dress belonging to Payne’s friend indicated that it matched with fibers on Whiting’s sweatshirt, Payne’s coat, her hair, and inside Whiting’s trouser pockets. Although the defense attorney did put a spirited fight against the evidence from fiber analysis terming it circumstantial and leaving a gap of doubt, the jury was convinced that the fiber evidence presented before the court did put the suspect at the scene of the crime, and his past sexual offences was enough to convict him to life imprisonment. The evidence, which mainly was fiber forensics, portrayed Whiting guilty beyond reasonable doubt. Two entirely different techniques used in the analysis of fiber evidence The technique of burning fiber This type of fiber analysis entails burning a sample of the fiber in order to verify which type it is. This is because; every individual type of fiber in fabrics has a unique smell when burnt (Dunbar & Murphy, 2009). Natural fibers when burnt produce a smell similar to hair, which has been burnt. Fibers made from cotton when burnt produce a smell similar to paper being burnt. Akin to burning nylon fiber, emits a smell similar to smoldering tar. The technique of spectrophotometry This technique entails analyzing fibers on fabrics using a machine called spectrophotometer (Lee & Harris, 2000). It entails evaluating the characteristics of the fiber relevant to its interaction with the light, by identifying a fiber’s blue print based on how it takes up wavelengths in the infrared light upon exposure (Lewis & Sigman, 2007). No matter how similar fibers may be, they vary on how they interrelate on exposure to infrared light. Conclusion Forensics fiber analysis is a significant aspect in convicting offenders. Fiber forensics relies on the Locard’s principle, which suggests that when an individual have a close contact with a surface or a person, they leave behind traces and clues, which can be used to trace back to them. During forensics, fibers, which are found on the victims, are collected and associated with other fabrics, found on suspects. In the Sarah Payne’s case, fiber evidence was used to press charges and convict Roy Whiting to life in prison. When collecting and analyzing transfer of fiber, the method used to spin the fiber into yarn, the components of the fiber, the amount of time the contact was made, the force within which the contact was made with and the condition of the material is integral in determining the transfer of fiber from one point to another. There are natural fibers and synthetic fibers. Natural fibers are from animals and plants like wool and cotton respectively, while synthetic fibers are processed, and made from polymers. Synthetic fibers include rayon, polyester, Nylon, Acrylics among others. Fibers can be sampled through using tapes, tweezers and vacuuming. References Geberth, V.J. 2006. Practical homicide investigation: tactics, procedures, and forensic techniques. London: CRC/Taylor & Francis. Lewis, L. A. & Sigman, M. E. 2007. Forensic Analysis of Dyes in Fibers Via Mass Spectrometry, in Forensic Analysis on the Cutting Edge: New Methods for Trace Evidence Analysis (ed R. D. Blackledge). Hoboken, NJ: John Wiley & Sons, Inc., Doi: 10.1002/9780470166932.ch8 Innes, M. 2003. Investigating Murder: Detective Work and the Police Response to Criminal Homicide. Oxford University Press. Yount, L. 2006. Forensic Science: From Fibers to Fingerprints; Milestones in discovery and invention. InfoBase Publishing. Dunbar, M. & Murphy, T. M. 2009. DNA Analysis of Natural Fiber Rope. Journal of Forensic Sciences, vol. 54 pp. 108–113. Doi: 10.1111/j.1556-4029.2008.00906.x Lee, H.C., & Harris, H.A. 2000. Physical Evidence in Forensic Science. Lawyers & Judges Publishing Company. Read More