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11.1 Common Weave Patterns of Textile Samples

11.1 Common Weave Patterns of Textile Samples. Chapter 11: A Study of Fibers and Textiles. Fibers in Forensic Science. Fibers are class evidence. Fibers create a link between the crime and the suspect. As with hair, clothes shed fibers. Fibers as Trace Evidence.

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11.1 Common Weave Patterns of Textile Samples

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  1. 11.1 Common Weave Patterns of Textile Samples Chapter 11: A Study of Fibers and Textiles Sanders

  2. Fibers in Forensic Science • Fibers are class evidence. • Fibers create a link between the crime and the suspect. • As with hair, clothes shed fibers. Unit 5: The Study of Fibers and Textiles

  3. Fibers as Trace Evidence • Fibers may be transferred directly from victim to suspect of suspect to victim. • This is known as direct transfer. • As you can see fibers are in direct contact with victim. Unit 5: The Study of Fibers and Textiles

  4. Secondary Transfer • If a victim has fibers on his person that he picked up and then transferred to to a suspect, it is called secondary transfer. Unit 5: The Study of Fibers and Textiles

  5. Early Collection • 95% of fibers are lost within the first 24 hours of an incident. • Collect fibers after a thorough examination. • Only collect out-of-place fibers Unit 5: The Study of Fibers and Textiles

  6. Type of Fibers • What is the composition of the fiber? • Is it rare? • Where are the fiber found in relation to the crime scene? • What was the color? Unit 5: The Study of Fibers and Textiles

  7. Number of Fibers Found • How many fibers found? • More fibers suggest a violent encounter. • Where were the fibers found? • If they were near or on victim’s body, you can place the victim to the scene Unit 5: The Study of Fibers and Textiles

  8. Multiple Fiber Transfer • Are there more than one type of fibers? • Are there numerous sources? • More variety of fibers suggest longer contact or more violent contact. Unit 5: The Study of Fibers and Textiles

  9. Type of Crime Committed • Each crime has an expected pattern of contact between • Suspect • Victim • Crime scene • This pattern is reflected in fiber transfer. Unit 5: The Study of Fibers and Textiles

  10. Time Between Crime and Discovery of Fiber • Unless fiber location is undisturbed the value of found fiber is greatly reduced with the passage of time because fibers will be expected to fall off. Unit 5: The Study of Fibers and Textiles

  11. Sampling Fibers • Fibers are gathered at crime scene. • Special vacuums • Sticky tape • Forceps • Important to notate and record where the fibers where gathered from. Unit 5: The Study of Fibers and Textiles

  12. Testing Fibers • First task is to identify fiber. • Clothing • Upholstery • Carpeting • Try to match fiber to its source. Unit 5: The Study of Fibers and Textiles

  13. Testing Fibers With a Microscope • How light behaves when interacting with fibers can help determine the fiber. • Polarizing light • Infrared light • Can determine chemical structure of fibers. Unit 5: The Study of Fibers and Textiles

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