Chapter 4: A Study of Fibers and Textiles
Student Learning Objectives
Forensic Science: Fundamentals and Investigations, 2nd ed., Bertino & Bertino, 2015
At the conclusion of this chapter, the student should be able to do:
_____ 1.Describe the role of fibers as evidence in forensic investigations.
_____ 2. Explain if fiber evidence is considered to be class or individual evidence.
_____ 3. Relate Locard’s Principle of Exchange to fiber evidence.
_____ 4. Distinguish between direct and secondary transfer of evidence.
_____ 5. Provide an example of secondary transfer of evidence.
_____ 6. Describe different characteristics of fibers and fabrics including:
a. type of fiber
b. natural of manufactured (synthetic) fiber
c. fiber color
d. number of fibers
e. weave pattern of fibers
f. relative thickness of the fiber
g.
_____7. Explain the significance of the following questions a forensic examiner might
ask the evidence collector when examining a fiber from a crime scene:
a. Where was the fiber found?
b. What was the source of textile that contained the fiber?
c. What type of crime was committed?
d. What was the time between the crime and the discovery of the fiber?
_____ 8. Describe several different techniques used to locate and collect fiber evidence
from a crime scene.
_____ 9. Discuss how the use of technology has improved fiber examination including:
a. Polarizing light microscopy
b. Infrared microscopy
_____ 10. Describe some methods of examining fibers that result in destroying the fibers.
Include in your answer the terms:
a. Burn testing
b. Solubility testing
_____ 11. Compare and contrast the terms fiber, thread, yarn, fabric, and textile
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Forensic Science Fundamentals & Investigations, Bertino & Bertino
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_____ 12. Compare and contrast natural and manufactured (synthetic) fibers.
_____ 13. Describe sources of natural fibers, including animals, plants, and
minerals.
_____ 14. List several examples of animal fibers used in textile production.
_____ 15. Describe a source of different textiles made from plants.
_____ 16. Describe the variation in thickness and stiffness of different type of plant
fibers.
_____ 17. Provide examples of materials produced from the different parts of the plants
listed below:
a. Seed fibers
b. Fruit fibers
c. Stem fiber
d. Leaf fibers
_____ 18. Contrast the chemical composition of animal fibers to plant fibers.
_____ 19. Describe the chemical composition of asbestos.
_____ 20. List examples of manufactured (synthetic) fibers.
_____ 21. Explain why rayon is considered to be a regenerated fiber.
_____ 22. Explain what polyester, nylon, acrylic and olefin all have in common.
_____ 23. Examine and distinguish among different types of fibers using a compound
microscope.
_____ 24. Explain how fibers are formed into yarns or rope.
_____ 25. Describe how to take a thread count.
_____ 26. Distinguish between the warp and the weft threads in a woven pattern of a
textile.
_____ 27. Describe different weave patterns.
_____ 28. Given a fabric, calculate the thread count per square inch.
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Forensic Science Fundamentals & Investigations, Bertino & Bertino
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_____ 29. Examine a textile sample and determine:
a. Weave pattern
b. Thread count
c. Type of fiber—natural or synthetic
_____ 30. List the physical characteristics used to identify a fiber.
_____ 31. Describe the chemical testing used to identify a fiber.
_____32. Describe the microscopic testing used to identify a fiber.
_____33. Cite arguments to support the claim that fiber evidence is considered to be class
evidence.
_____34. Cite arguments to support the claim that fiber evidence is usually considered to
be circumstantial evidence.
_____35. Describe the forensic techniques used to determine if a fiber or textile from a
crime scene is consistent with the evidence fiber or textile from a suspect.
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Forensic Science Fundamentals & Investigations, Bertino & Bertino
3