Hair analysis is a useful tool to use when determining the species of a specific specimen.  I say species because based on my observations and what I saw under the microscope when I compared my hair to my partner’s hair, it would be very difficult to differentiate between two humans.  I am only a student, and I don’t really know how to compare hair samples, but after the lab, I imagine it would take a lot of skill and microscopic detail to match a hair sample to an individual person without testing the DNA.  That being said, it was easier to differentiate between the human hair samples and the dog/cat fur samples.  When looking at the dogs fur under a microscope, it was thinner than a human’s and it had an intricate pattern on the inside of the hair.  The cat’s hair also had this, however, it was even thinner than the dog’s and human’s hair/fur.  That was the easiest observation to make about the differences.  The hardest observations to make were about the root of the hair.  Although we didn’t have any root samples of the pet hair, I had two root samples of human hair from my partner and I.  When comparing the roots, they looked exactly the same to me.  It was only after moving it around a little bit that I notice my root was moore flexible than hers.  My root would move side to side like it was swaying, and hers would just stay in one spot even if we moved the hair sample.  Looking back at the lab, I think it was helpful to personally see some real samples of hair and fur to compare and observe, however, it was more difficult than I thought.  I think in order to link a specific suspect to a crime, you would need a very skilled professional to study the hair specimens for a long period of time.
