This story line has too many gray areas to be taken on face value for me. Why would the girl walk down the stairs after the boy got shot? What proof is there that they broke into the house? Maybe waiting till the next day was b/c the guy needed to arrange his story and create the break in scene.
this.... dragging bodies across the floor, finishing shot, girl laughing at him when rifle jammed.... "it rubs the lotion on its skin" cuckoo....