Here is something that most of you do not know (judging from some of the comments), according to the state fire marshal (they guy who can come in at any time and lock your doors until you do what he says is law) you can NOT (and I stress NOT), lock the doors of any place of assembly while an assembly is taking place. I've been fighting with him on a church that wants access control on all their doors and what I had to do to get approval is crazy, but to give you an idea here it is:
1. request to exit motion (this automaticlly unlocks the door as you approach),
2. request to exit button (this is backup incase the motion fails, Not likely)
3. During "open hours" the system must automaticlly unlock the doors.
4. they have a card (or will have once the system is in place) to unlock the doors to the sancuary while they are holding services.
On top of that, they have a "child development cented" on site which from my limited understanding, you can't carry, it's treated like a school. So they are screwed.