I've seen no info on how many rounds he brought with him.
6 minutes start to finish, including suiting/loading up, getting to the 3rd floor and targeting whoever among different rooms.
Important New Information:
* Moreover, it is reported that the administrators at Marjory Stoneman Douglas recommended in January 2017 that the Broward County School Board conduct a “threat assessment” on the killer. It is undetermined at this time what, if anything was done.
^^^^^This goes to the Culpability & Liability of the Broward County School Board^^^^^
Even more distressing is the report that the police were called to this individual’s home dozens of times over the last years. Yet, this information was never matched with the other warning signs from the school and the FBI to address the growing threat. It is not enough to only question if the appropriate action had been taken last year, could the horror we now face have been prevented – we must demand better, and hold those accountable for these failures, so that it does not happen again.