What is the possible liminations of using hair as evidence in crime investgation s\

A limitation of using hair as evidence from a crime scene is that hair can not be directly linked to a suspect. It is impossible to say that a hair sample came from only one specific person.

How it got there. Anyone's hair can be carried and blown from anywhere, if so you'd have to go through every persons dna that had contact with a victim and contact with the contactie and so on and so on.