Fibers provide one of the most common and important type of trace evidence retrieved in forensic investigations. They are transferred from one surface to another in any case where contact has occurred and may have quite high evidential values to link individuals and locations. Fibers are examined in two phases: identification (classification) and comparison. Identification or classification of a fiber is an antecedent to its comparison, whether to a known source or to other questioned fibers. These examinations include a scheme of analysis using physical, optical, and chemical properties. Instrumentation useful in fiber examinations include microspectrophotometers (MSP), energy dispersive X-ray microanalysis (SEM-EDX), Fourier transform infrared spectrometers (FTIR)/microscopy, pyrolysis gas chromatography-mass spectrometry (Pyr-GC-MS), among others, confirm or determine the polymer composition of manufactured fibers.
