Fibers are one of the most ubiquitous forms of trace evidence. Textiles surround us at home, at work, in vehicles, and in our social environments.
Trace material such as fibers are fairly unique to an individual’s environment because the choices in clothing, vehicles and home décor are based on personal preferences. Fibers transferred from an individual’s personal environment can also be secondarily transferred in a crime. The idea that two people could be wearing the exact clothing on the same day is unusual therefore the idea that foreign fibers on a suspect or victim that share the same characteristics after a discriminating analytical examination is also very unusual.
We use a variety of instruments during fiber examinations, all of which consist of a microscope. Figure 1 is a comparison photograph taken under a microscope of fibers in question and fibers from a known source.
Ropes and cordage may also be submitted to the Laboratory for analysis. These are either composed of synthetic or natural fibers. Thus, the same analytical scheme is used as with a fiber examination. An association between the rope or cordage in question and any known ropes submitted can be determined.
Fibers can be transferred as easily as they can be lost so lack of evidence doesn’t always indicate lack of contact. That is why collection and packaging of fiber evidence is important.
Collection and Packaging of Fibers and Cordage:
- If possible let the laboratory remove fibers
- Package question and known items separately
- Consult the Trace Collection section for further information