You just reminded me summer...I meant to post these a few days back after I mentioned the hair root banding...
First is from Caylee Anthony case...
An FBI hair analyst testified today that a hair found in the trunk of Casey Anthony's car likely came from a dead body.
Karen Korsberg Lowe said she felt definitively that the sample of hair removed from the trunk showed post-mortem banding -meaning that hair was consistent with hair from a dead body, not a live one.
"It has a darkened band at the root portion of the hair. This is consistent with apparent decomposition," Lowe said during the court session this morning.
http://abcnews.go.com/US/casey-anthony-trial-fbi-analyst-hair-car-trunk/story?id=13760229
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This link has quite a lot of info about it...one point it mentions is that this root banding only seems able to be detected post mortem from around eight hours after death.....
Although our data suggest that it may take several days to develop
postmortem banding, it has been reported as occurring in as few as
8 h (1). Why only a select few hairs demonstrate root banding is not
known.
http://library-resources.cqu.edu.au/JFS/PDF/vol_46/iss_1/JFS4610015.pdf