Hair and Fibers&Textiles Flashcards
What are used to link between crime and suspect?
Fibers
What kind of evidence are fibers?
Trace evidence
If fibers are transferred from victim to suspect or suspect to victim, what kind of transfer is it?
Direct transfer
Fibers were transferred from the original source to a suspect and then to a victim. What kind of transfer is it?
Secondary transfer
Within 24 hours, what percent of all fibers may have fallen from a victim or been lost from a crime scene? Because of this, what is important?
Estimated 95 percent; early collection of fibers in an investigation is critical.
What kind of fibers are investigated?
Fibers that are not expected to be found.
What are few characteristics forensic scientists might question about fibers?
type of fiber, fiber color, number of fibers found, where the fiber was found, textile the fiber originated from, multiple fiber transfers, type of crime committed, time between crime and discover of fiber.
What determines the value of fiber evidence?
Fiber’s uniqueness
What the many number of fibers suggest?
possible violence or a longer period of contact
Fibers are gathered with what?
Special vacuums, sticky tape, and forceps
What are the methods that can analyze fibers without damaging them?
polarizing light microscopy and infrared spectroscopy
What uses a microscope that has a special filter that allows the scientist to look at the fiber using specific light wavelengths to examine fibers?
Polarizing light microscopy; how the fiber appears tells scientist what type of fiber it is.
What emits a beam that bounces off the material and returns to the instrument?
Infrared spectroscopy; how the beam of light has changed reveals the chemical structure of the fiber.
what kind of testings can scientist do if there are large quantities of fibers?
Burning them in a flame or dissolving in various liquids
What can you call things like clothing, carpets, and upholstery?
Textiles
What are fibers that have been spun together?
yarns
What are two classifications of fibers?
natural fibers and synthetic fibers
What fibers come from animals, plants, and minerals that are mined from the ground?
Natural fibers
what are three sources of animals that provide fibers?
hair, fur, and webbing
All animal fibers are made of what?
proteins
Is fur a textile?
no
what fibers are the most popular of animal fibers?
hair fibers