TB did it.
GB and Flower was sitting on the bench, talking. TB was looking out the window, aiming at them. TB killed them, and thrw the revolver in the pitcher. He pulled them into the meat locker and hung them by the gun wounds. There was already meat on the hooks so he threw them off. GB's scrape was caused by being dragged on the floor. He then wrote the note, and went out.
Green is the killer because his room is placed directly above it.
He got a evreyone's pajamas ( Weird. ) and set them on fire with gasoline.
The fire was small, though. So she got a necklace and spread the fire. He threw the necklace out of the window, and then evacuated. The door handle was made of a unburnable metal so he got out. The blood was from one of the shards of the fish tank. And all those burnt stuff were from the fire.
Killer: Specter
He haunted the tv and had the message show, then Tangerine saw the message, dropping the plate, and came outside to the tree. Specter dropped the bomb and exploded the place, leaving the remote for the bomb on her arm.