FIBERS

ABOUT FIBERS

• Fibers are gathered at crime scenes
• Collected by tweezers, vacuums, or tape
• They come from furniture, clothing, drapes, etc
• They are determined to be either manufactured or natural

COMPLICATIONS

• Fibers are not unique
• They cannot pinpoint or confirm an offender
• Other factors can help back up the evidence

ORIGIN

• Natural fibers come from plants (cotton) or animals (wool)
• Manufactured fibers are synthetic, such as polyester or acetate
• They are made from long strands of molecules called polymers
• Some fibers can be classified as both natural and manufactured

ANALYSIS OF FIBERS

• Compound microscopes
• Phase contrast microscopes
• Scanning electron microscope
• Spectrometer
• Micro-spectrophotometer

ANALYSIS CONTINUED

• Observe the color and diameter
• Dyes can be analyzed with chromotography
• Under the microscope:
• Observe any abnormal tears
• Analyze the strands and strand behavior

WHAT TO LOOK FOR

• Shape
• Dye color and content
• Size
• Chemical composition
• Microscopic appearance

FURTHER ANALYSIS

• Analysts get very few strands to work with
• A lot of their research relies on close observation
• They need to be very careful not to alter the strand

MICROSCPES

• Microscopes use light to make the fiber more apparent
• Different microscopes focus on different aspects of the fiber
• They provide high resolution and a depth of focus

SPECTROMETER

• Separates light into component wavelengths
• The passing of light emphasizes certain parts of the strand
• Yields a way to identify different types of substances

IMPORTANCE OF FIBERS

• They can help solve a case
• May lead to a potential suspect
• Helps a case if other evidence is unhelpful
• Usually has very specific properties