In this scenario the killer is there to murder their supposed intended target. I say go immediately murder that target so you definitely accomplish what you’re there for. But ok, I’ll go along with wanting to get rid of possible obstructions so they can take their time with their victim. I could buy taking E out first because he could be trouble & overpower the killer. Then of course X has to go too. But then just leaving the 1st floor girls makes no sense. They could’ve been calling 911 (cops were very close!) while E&X were being stabbed. If this was a planned & targeted murder, you can’t just plan on the 1st floor girls doing nothing.
And of course the 1st floor girls didn’t hear anything & didn’t call 911 (not victim blaming, just stating facts) - but I think if the plan was to get rid of obstructions before going for the target, the 1st floor girls would have definitely been part of the plan.
MOO