Which techniques are commonly used in hair and fiber analysis?

The correct answer involves the combination of microscopic examination and chemical analysis, both of which are essential techniques in hair and fiber analysis. Microscopic examination allows forensic scientists to observe the structure, color, diameter, and other physical characteristics of hair and fibers, helping to differentiate between various types and sources. This technique can reveal detailed information that is crucial for linking evidence to a suspect or victim.

Chemical analysis complements microscopic examination by identifying the chemical composition of the hair or fiber. This can include methods such as spectrophotometry, chromatographic techniques, and mass spectrometry, which help determine the material's origin, such as whether it is of human or animal origin or identify synthetic fibers. The combination of these two techniques provides a robust framework for accurate and reliable forensic analysis, ensuring that results can support investigative conclusions.

Other options mention only one of these techniques or rely on visual observation and speculation, which would not provide the level of reliability and scientific rigor needed in forensic investigations.