This is a horrific case. I only caught up with the release of the affidavit yesterday and there are quite a few things which are baffling.
Kayle had moved out and was visiting for the weekend; if she was the target then how did he know she was there? I'm not clear on when Kaylee arrived and whether he'd watched the house since her arrival.
The knife sheath is odd, if you were planning to surprise two sleeping people then surely you would take the knife out of the sheath before you entered the room and put the sheath in a pocket to make sure you didn't leave anything behind.
If it was a renowned party house then he was taking a risk that there wouldn't be other people in the house in addition to the housemates and he hadn't been surveilling the house for long enough on the night in question to be certain about who was in the house. His phone data suggest he didn't arrive in the area until long after they had all arrived home. 12 surveillance visits over a matter of months does not seem enough for him to know about the routines of all housemates.
I wonder if he had been in the house before and placed hidden cameras to monitor the comings and goings.
If he came in on the first floor then he would have walked past B's room to get to the second floor and if he came in through the sliding door in the kitchen on the second floor (which is at ground level at the back of the house) then he would have walked past D's room at least three times whilst he was there.
Why attack the people in rooms where there were two people and leave the people sleeping on their own alone? There is a much greater risk of things not going according to plan if you have to subdue two people at the same time. Even if he'd been disturbed by Ethan or Xana then why not run if they were not his intended victims.
I think he killed the people he intended to and I doubt this is the first time he's done it.
I really hope the police have dotted the i's and crossed the t's on everything so far, apparently he has a number of lawyers offering pro bono work to make a name for themselves and it would be a travesty if he walked on technicalities.