Just thinking outloud here...
But the hose coming out of the house really has been bothering me... I think, obviously the crime occured in back right of the house.. what we are
assuming to be Zahra's room... What if EB and AB switched rooms and placed a waterbed over a large area of blood.. and had also painted the room.. Giving the
appearance to the LE that it was their room... and told LE that Zahra's room was in the front of the house... Maybe that tarp that S. Homey saw was the waterbed mattress... and the wood was parts of the waterbed... I think that Zahra has been gone for some time before LE was made aware of it...