He's been connected to that house his whole life, and he has carpentry skills. I wouldn't be surprised if they strip it down to the studs. Maybe not quite as comprehensively as they took apart Gacy's house - a lot of that was to give them access to the remains in the crawl space - but they're going to be looking in walls and under flooring. This guy had a deep connection to his home, and strikes me as the sort who'd hide things in the fabric of the building itself. Just knowing they were there would give him a thrill, even if he couldn't see or touch them. Since he's such a packrat, I hope he kept something from every single person who had the misfortune to come across him. Not just Melissa, Amber, Megan and Maureen, but others found on or around Gilgo, others we don't even know about who were found elsewhere or maybe never found. (For example, I strongly believe Jamie Seymour fits his preferred victim profile in every way.) I hope he kept everything, and that they're able to use it to bury him.
Since someone who lived there is also obviously a gardener, I definitely think we're going to see them digging at some point before they wind up their search of the property.
MOO