I had actually been wondering:

How many of the dead were shot, rather than died because there was a shooting going on (shrapnel, trampling, etc)?

How many of the injured were shot, rather than injured by shrapnel or from themselves or others trying to get away from the shooter?

I had a talk with an EMT gun enthusiast friend of mine, and he said you can't aim with a bumper stock, so we thought maybe of the injured (500ish) 150 shot 50 shrapnel 300 other injuries, and of the dead, higher proportion shot, maybe 45. Total guess. What do other gun or EMT experts say?