I'm not familiar with it, either, but I've been trying -- looking online for a discussion of hair indicating how many days since the hair donor was alive, etc., but I haven't seen anything -- but I'm not a lab guru nor am I a forensic professional. Dunno. I would think something about a hair strand might look different if the donor has died, but I have no idea.
Perhaps if I had known the correct combination of search words in google, I might have had more luck, but I did try for a while with no results on hair indicating TOD. Maybe someone else can come up with ter search criteria.