[trebb]

It could have been kept in the room until after he blocked the stairwells, etc. Once he started firing, the chance of someone worrying about it and fetching it were pretty slim - plus he could fire shots through the door (and probably walls) to discourage them...awful slim to develop a conspiracy theory from.

[freedomjusticeruleoflaw]

I would say there is more than the cart at this point.