LE has NOT specified that they found the "human remains" buried. So people posting here about the remains being buried are just speculating. The only thing that has been revealed is the word "human remains", either due to:
1) Natural decomposition
2) BL cutting up the body
and/or 3) very likely, black or brown/grizzly bears being involved in their annual hyperphagia massive eating marathon every autumn to fatten up before hibernating in their dens for the winter.
If BL harmed GP and caused her death, the degree that the body has decomposed and what gets recovered is crucial to convicting BL, assuming he did it and is caught alive. DNA will identify whether the remains belong to Gabby. If there are bullet holes in the skull, for example, that is damning evidence. But if GP died due to more superficial wounds inflicted by BL, and the remains have been heavily eaten by bears along with 3 weeks of decomposition, foul play could actually become very hard to prove. :-( During this annual period of hyperphagia by bears every autumn, bears will also crunch on the bones to get their calcium nutrition, so the bears would have destroyed lots of forensic evidence if the bears feeding were the main cause of the "remains" :-( With an intact body, you can pinpoint skeletal damage due to strangulation, blunt force trauma, etc. But convicting BL, assuming he caused her death, is far from guaranteed if bears fed on the body for 3 weeks. :-(