Media reports are it was a party house, with several parties every week, with numerous people knowing the key pad entry code. So, there would be DNA present from every party attendee, and massive amounts of comingled blood through much of the house. Plus the dog tracking throughout the house, contaminating everything.
There's a floor plan posted online. Killer would seem to have been familiar with the residence, habits of the inhabitants, and with the dog. Logically, seems like the male was killed first, biggest threat and closest to point of entry. GF woke up, had defensive wounds before expiring. Then proceeded to the third floor, killed one girl, second also had defensive wounds.
Who fits all of the familiarity and may have had motive? Seems like the ex-BF of the one 3rd story girl, and you can speculate as to a possible motive beyond just the break-up. And why he didn't answer his phone when the 2 girls called. BUT, his DNA legitimately would be in the apartment, so need far more evidence than that. That's the enormous challenge for LEO, tie things down enough to limit plausible explanations for evidence at the scene, for reasons other than the attack.
But lots of others have equally compelling hypotheses, to be sure.
www.seattletimes.com
