It looks like he may not have confessed at all nor showed them where the remains are.
From your link:
"Investigators confirmed they have not found her remains."
So this may be the story he told whomever came in and finally ratted him out.
The only thing they found missing was her purse and keys. A perfect ruse to make others think she had ridden off with someone else. Nancy Grace said the house was pristine with everything in its place. If he went there to do a real burglary there would be closet doors open and drawers pulled out. Nancy also said they found clay on her car tires and she always kept her vehicle neat and clean. So he may have used her own vehicle to transport her thinking people would think it was Tara driving away from her home and then brought it back.
LEs theory of the case may change as more investigation is done. Its really like a new investigation now that they know who the suspect finally is but had no clue for years that he was any way connected to her murder. Unless this guy was a drug addict back then and there is no evidence of that I don't think he would pick a school teacher's home to break in knowing they make very little money especially in a small town like Ocilla. And if he was really there to do a burglary and only took her purse and keys then he knew beforehand she would be home in order to obtain those two items. He takes her keys but not her vehicle? He didnt come there to do a burglary, imo.
Even if he is saying this was the reason he knows even if they locate her remains now they cannot prove he went there to sexually assault her since there would be no evidence of that this many years later.
Do we know for sure if the dogs were never brought inside of her home? The reason I asked is even if the person was killed in their home if they were taken out quickly the cadaver dog wouldnt pick up a scent of decomp. Iirc it takes about 45-70 minutes for decomp to set in once a person is deceased. Imo, by then she was gone from her home.
In the Scott Peterson case the police and DA believed Laci was strangled on her bed and then soon after bundled up in a tarp and hauled to the SFB in his boat where he disposed of her and Conner Yet the cadaver dogs did not alert inside of her home.
IMO