One other question relates to all the pictures shown of the kids walking out of the building in line with their hands up. Weren't they checked before they were allowed out of the building?
Probably not.
Were cops going to shoot them if they didn't have their hands up?
Could be, yes. At that stage the shooter may well have blended in with a group of students who didn't see him shooting. Which is exactly what happened at Parkland (although he was unarmed at that time).
It just seemed odd to me. I saw similar situation with the youtube shooting. A bunch of people walking out of the building with their hands up. I assume that is some sort of procedure, I just don't see the point.
The guys clearing rooms don't have time to search each person, patch the wounded, and conduct a full debriefing. Their job is to shoot the bad guy a whole lot and as quickly as possible. To save time, they (or more likely the next guys in) will herd the masses out to be "washed". Outside (ideally speaking) will be cops who will process each kid looking for guns and injuries and sort them properly. If it's a scenario with a limited number of hostages where there is a known good guy with knowledge of the situation (such as the bus driver in a bus takedown) they'll park that known good guy out front with the washers to point out the bad guy or anyone who doesn't belong.
Until the washing, everyone is told to keep their hands up (or on the shoulders of the person in front of them). If that's you, you definitely should do that too.
