Casey Sheehan’s Grave

Bookworm was rather suddenly called away on a trip, so I'll be pinch-hitting for a while.  Right now, all I've got is a question.  My father sent me an e-mail with a picture of what was supposedly Casey Sheehan's grave, without a tombstone.  Does anyone know whether it is true that his parents haven't bothered to put a headstone on their son's grave?  Hard to imagine Cindy's handlers would allow such a negative symbol to exist. but does anyone know for sure?