I have watched the video of the police spokesman. Some contradictions:
They did not know where the shooter was, but they had him holed up in a classroom.
They were taking fire, but did not know where the shooter was.
The shooter was barricaded so they could not shoot him, although he was shooting at them.
They could not get the door open, but he was shooting at them.
Did they ever think to just blast the door down, the way it is done on TV?
Maybe they should have asked for a key like to Border Patrol agent that finall took out Ramos.