I wonder if they got samples from shoes, carpet, car tires, or something like that and lab results were able to determine it is from one of those rock quarry type areas and that is why they are searching areas like that.
If so, a lot of people could actually landscape some areas in their yard with that type of stuff ie bigger rocks etc. Could DB be so diabolical to bury Lisa in someones lawn, soft dirt rocks on top, if it is soft dirt heck you can dig deep enough with your hands. Place the rocks over it. If Lisa is found, then DB could try to blame said neighbor. Could this neighbor also be the one she was drinking with. Could DB have staged the store, inviting the neighbor over and planned this entire thing? Just a few open thoughts going through my brain. MOO