According to a very coherent eyewitness in the Colorado theater where the shooting took place — a man sitting near one of the fire exits in the front row received a phone call near the beginning of the film feature.
This phone call struck the witness as odd due to the fact that the man did not leave the theater after he began to talk on the phone.
Just after the man disconnected the call he went to the fire exit and propped the exit open with his foot in some way and possiblely a shim of some type directing or waving another person toward the direction of the exit door.
According to the witness, about 15 minutes into the film the fire exit door swung open and a man about 5’9″ fully decked out in tactical clothing and heavy body armor entered the theater by throwing a canister of toxic gas into the crowd.
The fact the the shooter was not alone is now out of the bag as authorities are covering up what appears to be a massive PSYOP and/or staged operation in some type of MKULTRA fashion.
Some of the equipment and body armor used by the shooter is illegal and hard to obtain unless you are military or law enforcement.
The gear used by the shooter would have ran him tens of thousand of dollars even if he could legally obtain it. This again signifies possible military or law enforcement involvement.
Here is the CNN clip where the eyewitness admits there were at least two people involved;