From Moscow Poloce:
We remain consistent in our belief that this was a targeted attack, but investigators have not concluded if the target was the residence or if it was the occupants."
I hadn’t thought of this angle, that the residence could have been a target. Is it plausible that someone would target the residence simply to make a statement? Sort of like they are sick of all the partying, in general, so don’t think about moving in here because it is not safe. If that is the case, then I would say that is not an isolated attack because someone sick of the partying could strike just down the road. Certainly this is not the only party house.
So why else could the residence been the target?