The victims being treated there ranged in age from 3 months to 45, the hospital said.
Denver Health Center had six patients from the shooting, one in critical condition and five in fair condition, said Shelly Davis, house supervisor.
Swedish Hospital in Denver was treating three people, two of them in critical condition and one in fair condition. A fourth patient with minor injuries was treated and released, spokeswoman Nicole Williams said.
Children's Hospital Colorado said it had treated six adult victims, one of whom died. And Parker Adventist Hospital was treating two people for minor injuries, according to a spokeswoman.
It may take hours or even days to clear Holmes' apartment, Oates said.
Investigators looking into a window with a camera have seen a sophisticated booby-trap with trip wires connecting incendiary and chemical devices, he said.
Oates said he has never seen anything like it.
A woman who lives across the street from where the suspect's apartment said police evacuated her building around 4 a.m.
"They told us there was a bomb or bomb material located in the house across the street from us." Rebecca Bradshaw said.
Law enforcement officers who searched the suspect's apartment found "items of interest," a federal law enforcement source involved in the investigation told HLN. He did not elaborate.
Bureau of Alcohol, Tobacco and Firearms agents were involved in the apartment search, agency spokesman Tom Mangan said.
In addition to looking into the possibility of explosives, ATF agents also are conducting emergency traces on the weapons to see how they were obtained, Mangan said.
Authorities also searched the suspect's car in the parking lot of the movie theater.
In addition to canceling his Florida campaign appearances, Obama pulled some advertising in Colorado.
Warner Bros., the studio behind the movie, said the company and filmmakers were "deeply saddened" to learn of the incident. The studio canceled the movie's Paris premiere, while New York police Commissioner Raymond Kelly said his officers would watch over screenings of "The Dark Knight" to prevent copycat shootings.
The National Theater Owners Association said in a statement that its members would be reviewing security procedures in the wake of the shooting.
The movie theater where the shooting took place has not been the site of any security incidents, said Timothy Warner, CEO of Cinemark Theaters, which owns the complex.
"You know, obviously you know, the person made a well-organized ... and had an assault weapon that would probably overpower any security that we would've had," he said. "I mean, this is obviously a very deranged gunman that had access to very high powerful weapons."
Aurora, a Denver suburb, is about 13 miles from Littleton, Colorado -- site of the April 1999 Columbine High School massacre.
In that incident, two teenage students, Dylan Klebold andEric Harris, armed themselves with guns and bombs and opened fire inside the high school. They killed 13 people and wounded 23 others before killing themselves.