The police really screwed up on this one

if they thought an insane killer was in the building, they should have evacuated right away. Not sat around to see how things play out... because of them, several people died. also, since they were looking for a specific girl, they could have made an announcement about that too. Instead of just telling everyone to go outside. and they don't even bother to check each person as they leave. they could have at least done that. and finally, it seems pretty stupid to only have 2 cops watching a house, one on either side. with a killer on the loose, they should have at least TWO on both sides. so he doesn't get the drop on people.... like he did. Frankly, their efforts to reduce the amount of trauma she would go through by letting her have her prom, actually led to more trauma, in losing all the people she cares about. yet again