Hair can be found microscopical similar to other samplings and therefor could help eliminate a suspect but not convict one.
Donated hair is cut off the head, not ripped out at the root, so the sheath that contains DNA will not even be present. Even hair torn at the roots often doesn’t have the sheath with it, and even if it does the sampling may or may not be big enough for analysis (perhaps mitochondrial?). Long story short, no, donated hair will not send the police to the donor’s door.
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