Why 2 windows shot out?
Could it be that many people were invited or even expected to show up? Could it be there were multiple shooters , who returned their guns to Paddocks room before the cops got there?
I can’t know. But one or two or three guns with plenty of ammo is all one needs for mass murder.
It would seem an obvious step to find and question everyone who rented a room on that side of the building. Maybe some chickened out.