Not likely,as all emergency door exits sound off with a buzz when breached from the inside,I too say someone opened it for him to come thru or the buzzer had been disabled prior.The timing of this horrible trajedy makes me wonder also if it was a staged event,false flag etc,especially after the damaging to their cause"fast and furious"scandal being brought to light just several months prior to the UN's small arms treaty.My hunch on this is certainly no less belivable than our govt"knowingly allowing foreign criminals and cartels to buy arms and explosives here in the US"so as to at a latter date ,criminalize our second ammendment.Surely we can atleast all agree our rights are under attack by a rouge element in our govt.We may not always agree on the details and try to split hairs with one another,however lets keep that fundamental fact in focus and come together united ,fighting for our common cause.They said that he walked in bought a ticket, propped open the emergency exit, got suited up and came back in that way. Nothing about multiple shooters