Doubt they're going to get anywhere unless someone fesses up. Too much time has gone by.
The thing that stands out to me is he was supposedly not found for several weeks after the initial search was called off, in a wooded area that was covered in the original search by the local authorities (anywhere from 25-150 yards from where they set up the search depending on which source you read).
This story has some additional info (also says 25 yards wheras the linked story shows 150)
Sounds to me like the body was dumped. Dunno how long it takes for animals to do their thing tho. I started to google it but after looking at the keywords I was using to refine the results, I seriously started to think I should stop before someone came knocking.
I did find that it takes 30 vultures approx 5 hours to reduce a body to bones, but it took them a while to find the body. www.newscientist.com