Officer John Gonzales was the first police officer to enter the theater.
While previous reports have suggested the attack was over by the time he arrived, he now believes he heard gunfire when he waited outside one of the theater doors.
If you can't see the video, click here.
Hear from eight of the responding police officers who ran in to Theater 9 the night of July 20, 2012, along with so many others, to help rescue the wounded and subdue the shooter. Our story on their story airs Wednesday, July 19, at 9 p.m. and 10 p.m.