Feel free to do all the digging you like.
As horrible as this case is, and the likelihood of Gannon coming home alive is rather improbable, I'm actually really looking forward to seeing what evidence was actually collected (stuff we're debating right now), and how it was either ruled out as inconsequential, or ruled in as proof that there was an actual crime committed, with that house possibly being the primary crime scene. "Looking forward" sounds sort of creepy, but I just mean looking forward to being impressed by how LE do what they do, and catch the monsters that do what they do.
I do believe they will bring Gannon home, one way or another, and the person who made him disappear will pay for it.