It would seem to me when trying to figure out whom the perp was, one would begin with the best immediate evidence. Victims are the first IMO, they saw it. Besides whom was the first victim shot, hum, could be a clue there.
Next there is physical evidence which must be gathered i.e. brass, spent rounds, recorded voice and visual. These things MUST be pinned down ASAP. It is called a crime scene and requires more than just putting up the yellow tape.
The fact that nothing was released soon after the event i.e. police are looking for a WMA or BMA approximately so tall, weighing about so much, wearing these clothes last seen moving in such and such direction on foot, at a minimum. Rather, all the announcements were stay sheltered, no other info available is BS.
They could have used local talent from the Bocce Courts on The Hill to find out who did it. He would be with the fishes now.
There is something that sounds very odd about all of this, apart from the abnormality of someone bursting into a room and killing people.
These days, the best approach is just to sit back and wait for Information, but here we are going on two days out, and they have nothing.