Fiber Analysis

Which of the following observations are used to help identify a specific fiber?

• smell of the burned fiber

• on contact with the flame, does the fiber coil or melt?

• color and structure of the residue left after the riber burns

• all of the above

All of the following are characteristics of a synthetic fiber except

• They are formed by combining monomer compounds into polymer molecules.

• They are man-made.

• They are used in the production of carpet fibers.

• They do not contain any natural fibers.

Tags

NGSS.MS-PS1-3

Fibers are an excellent source of trace evidence because

• They are easily transferred from victim to suspect.

• They are often overlooked by a suspect.

• They can be easily collected and stored.

• All of the above.

A fiber is collected at a crime scene. When viewed under a compound microscope, what two traits would indicate that the fiber was a human hair and not a piece of fiber obtained from an article of clothing? (Choose 2)

• the presence of a cuticle

• a medullary index of 0.33 or less

• a wide diameter

• its ability to dissolve in water

When fibers are transferred straight from victim to suspect or suspect to victim, this is called:

• necessary transfer

• direct transfer

• absolute transfer

• secondary transfer

The transfer of evidence such as a fiber from a source to a person, then to another person, is called:

• direct transfer

• absolute transfer

• source transfer

• secondary transfer

Which of the following properties should be examined when comparing two fibers?

• Color

• Diameter

• Cross-section

• All of the above

Which of the following is not a synthetic fiber?

• Rayon

• Polyester

• Acrylic

• All of the above are synthetic.

Tags

NGSS.MS-PS1-3

When observing a cat hair image under the microscope, it is possible to contrast it to a human hair by observing the —

• DNA

• distribution of pigment

• medullary pattern

• presence of keratin

Rayon, a regenerated synthetic fiber, can be differentiated from a natural fiber by examining if it contains fibers from —

• cotton

• nylon

• polyester

• cellulose

Tags

NGSS.MS-PS1-3