I’m inclined to believe the scene is not staged. Broken glass from door in bedroom suggests intruder broke in. It looks to me as though someone came up from behind her and strangled her (Perhaps while she was passed out from taking too much Percocet), which would suggest why she did not hear glass breaking, and during strangulation she was struggling and fighting (kicking, grabbing at couch and cushions trying to get free), hence the chaotic scene in living room. so far there are way too many variables that lead to several very different theories.
Raaj, when Mr. Moran said he left everything as it was he was referring to the crime scene. Whether or not he had that case with him when he got home, or if he left it there before he went to work it still should have been added to evidence inventory because it is a part of the crime scene.
“ Russell Moran: I didn't even notice the mess in the house at first. As you can see, the place looks like it's been ransacked. The glass from the door in the back bedroom is shattered. I left everything as it was. I can't believe a burglar would go this far.”
I think that suitcase was been kept by Mr. Moran in the morning as he said in the interview that he left things as it was now and then..also Kelly's body language shows little comfort so there must be someone she know very well has arrived to see her same day..
“ Russell Moran: I didn't even notice the mess in the house at first. As you can see, the place looks like it's been ransacked. The glass from the door in the back bedroom is shattered. I left everything as it was. I can't believe a burglar would go this far.”