How does a forensic hair comparison work?

A forensic hair comparison primarily relies on comparing the physical characteristics of hair samples. This involves examining various attributes such as color, texture, length, and diameter, as well as the scale structure on the hair shaft. Forensic analysts look for similarities and differences between hair samples from a crime scene and those taken from a suspect or a known reference to establish potential links or exclusions.

This method can be particularly useful in identifying whether hair found at a crime scene could have come from a specific individual, especially when the hair lacks viable DNA due to it being in the anagen phase (the growing phase) or when the follicle is not attached.

Other methods like analyzing DNA, performing chemical analysis, or matching against known databases provide additional information and may complement the findings from physical comparisons, but they follow different procedures and applications within forensic science. The emphasis on physical characteristics serves as a fundamental technique in forensic hair comparisons that can yield valuable insights during investigations.