I was under the impression that emergency exits were supposed to be locked to the outside with alarms when opened?
You nailed it. Now reported on Fox that he had previously opened the door so he could get in. Well played sir.
At the cinema, he entered through a fire door he'd previously left open and then set off some sort of explosive before opening fire with multiple guns, including an AR-15 assault rifle, a shotgun and at least one .40-caliber Glock handgun.
That's the most detail I've seen gun-wise thus far.
Grad school dropout's horrific attack came out of nowhere | Fox News