This is my first post here, after reading off and on for many years. I stumbled across this thread and wanted to comment, since I live in Dalton. Actually, I live walking distance from the home where this took place.
It is fairly common knowledge among those I've spoken with who the main suspect is, but no, he/she has never been officially named, so I guess I can't be specific. Like someone mentioned though, the comments section of the linked blog is very informative.
I do remember that they drained a pond at a residence near the home several years ago (I'm thinking late 90s) and word got around that they were looking for a murder weapon. As far as I know, nothing was turned up. If I remember correctly, the home had been owned by a family member of the deceased couple and they wouldn't allow it to be searched. When it was sold, the buyers agreed to allow the pond to be searched. At the time, my family owned a business in town and a couple of cops would come by every so often and chat. That's how I originally heard about the pond search, although it seemed like most everyone in the nearby area knew about it, so it may have even been on the news.
Aside from that, I don't have much to add. However, my stepfather has been a firefighter here for almost 30 years and knows absolutely everyone. I'll ask him if he knows anything about this case. I haven't thought about it in years, so I'm glad I came across this thread.