Fibers are everywhere! From the shirt you wore to work today to the blankets on your bed, fibers are in every aspect of our daily lives. Because they are so ubiquitous, they have a high chance of being transferred during a crime. If recognized and collected properly, fibers may be able to link various individuals and places involved in a crime. Fiber evidence is not just restricted to carpets and clothing. Any object that contains fibers is useful for investigative purposes. Some objects that have been tested in the past include: wet suits, window screens, wigs, towels and fishing line to name a few.
The collected fibers are submitted to the forensic lab where the analyst will perform a multitude of analytical tests. The analyst will be able to determine the type of fibers that were collected as well as whether unknown fibers are similar to known fibers of a scene. Determining the types of fibers found may also give an investigator some leads as to what objects were around at the time the crime took place.
The majority of the analyses performed for fibers are done so on a polarized light microscope. This microscope aides the analyst in determining many optical properties of the fibers which in turn helps the analyst identify the fiber type and compare those results to other fibers within the case.