FIBERS
Trace Evidence
Physical Properties
- Texture
- Length
- Color
- Shape
Chemical Properties
Absorbency
- its ability to take in moisture
- moisture regain
Wicking
- ability to carry its moisture along its surface
Electrical Conductivity
- Fibers that do NOT conduct electricity create
- Static electricity
Chemical Reactivity
- How it reacts to chemicals such as dyes, pigments,
- Soaps, detergents and bleaches
How Scientists Analyze Evidence
Fibers are very important because they can determine what the suspect was wearing and what kind of fabric it is to possibly trace it to the suspect. They have people with special suits so that their clothes or hair wouldn't mix with the evidence.
NC Science Olympiad: How to do a Fiber Burn Test
Case Involving Fibers
Dr. Jeffrey MacDonald, Army captain was accused of murdering his pregnant wife and two children in 1970. The investigators were suspicious of the doctor because of the nature of his wounds suggesting that they were not defensive and perhaps even self inflicted. Blue threads that matched the doctor’s pajama top were found under the body of his wife as well as in the bedroom of both murdered children and even under the fingernails of one of his daughters. When MacDonald was confronted with this and other evidence he reportedly stated “You guys are more thorough than I thought”