The entire parking lot around the Century 16 Movie Theaters has been blocked off.
Aurora Police Chief Dan Oates said there was no evidence of additional shooters.
FBI spokesman Jason Pack said there's no indication in the investigation so far of any connection to terror groups. There was no immediate word of any motive.
Just after the shooting occurred, a bulletin was issued to other police agencies throughout the metro area warning them of the possibility of similar incidences in theaters in their cities.
In Colorado Springs, various movie theaters have requested off-duty officers to monitor the theater. Colorado Springs Police is making arrangement to assist them. Police say they will also pay special attention to shopping centers and other places where people tend to socialize.