So the two blondes were sleeping in the same bed. Seems strange that at least one of them wouldn't scream. You can't kill two people at once. Strange case.
I have similar thoughts, but to play advocate, it's hard to say what kind of shape they were in after a night of partying. I could also envision a scenario where the attacker covered the mouth of one victim while simultaneously attacking the other, then going back to the first victim. There could also have been multiple attackers.
