Early reports were that someone answered a cell phone, then headed to the exit. After he sat down, the shooter came in the exit.
Of course this is all ridiculous, but this guy could win the lawsuit.
The first report I read about was he opened the exit door and propped it to stay open and then came back through it with his ‘stuff’. There really should be alarms on those exit doors as they are for emergency use anyway. And anyone opening it who know blaring alarms would go off.
The shooter bought a ticket juts like everyone else, went to his seat, then after the movie started got up and went out the emergency exit (and rigged it open), went out to his car that was 25 feet away, donned his gear and grabbed his guns and then went back in the propped open exit door and started firing.
The thought was that Holmes bought a ticket. Parked his car right out back. Not far from the door. During the beginning of the movie. He faked taking a phone call. Walked out. Got dressed. Got his weapons and came back in and started the attack. No where have I read that someone came back in and sat down and then the shooter came. I definitely have not seen that someone knocked on the door.
Evidence suggests Holmes acted alone.