Remember when Heather
After you do that, just listen to the distant mumbling of a high pitched voice and another lower one; obviously there was a conversation going on in there between two people, possibly between a female and a male.
Then you go into the dress shop and finish the cutscene, exit the dress shop to the main hall (the big empty one) again, notice that the sound/ mumbling disappeared.
So now my question is... (since the barely audible conversation didn't sound like a murder or anything close to it was going on)
Or maybe I'm just hypothetical, I don't know; but if they weren't monsters, what were they doing in there?
I think the Closer and the female (that is if they were actually humans) were in somekind of a sexual contact, then Heather came in and BANG! What she saw was completely different from what the situation actually was...
Woman: (lying on ground, amazed) "Umm..sorry but we're closed"
Heather: "STAY BACK! (raised gun)"
Man: "Whoa! Calm down.. Please, now there's no need for anyone to get hurt (slowly approachs Heather)"
Heather: (Fires multiple shots, probably killed the man with the first few shots and took care of the lady with the last few ones)