So, take it with a grain of salt, but apparently there's a rumor going around that started on 4chan and went over to reddit, and I've seen a little bit on twitter, but here goes.
The rumor is E and X were the targets, it all started because of an argument at the frat parry between two people who already didn't like then. Apparently E had been tutored by this person and thing did not go well, and the person was on roids which E made fun of him for. The other person is a girl and apparently the couple had been overheard fantasizing about murdering people before, it's believed after the fight they put those fantasies into action. It said the girl acted as a lookout and the guy did the killings. It also stated that 3 of the bodies were found in the doorway of the bedrooms and only one was truly in bed. Lastly it said the reason the two downstairs roommates were spared was because they were friends with the girl in the relationship.
The posts gives two names of who did it, and also says this is why Kaylees dad said they didn't have to go upstairs. It also said that Kaylees dad was incorrect about her having the worst injuries.
More to the story, it took 19 minutes from the walk there to the walk back. From David's house they could see the house and when the 3rd floor light went out is when they moved. They wore baggy close and electrician gloves, which one family owns a cleaning company and they were disposed of over Thanksgiving. David's mom is a paralegal and he knows not to talk. It says there were 4 people who went to the house, they entered through an unlocked backdoor and left through the front. Apparently there are pictures from the night of the murders of them in the house and behind the couch.