(CNN) - A police officer in a Denver suburb was seen carrying a young girl, described as bloodied and motionless, early Friday morning after a gunman burst into a packed movie theater during a midnight showing of "The Dark Knight Rises," the Batman movie sequel.
"I honestly can't think of any kind of person who would intentionally hurt a little girl," Alex Milano told CNN affiliate KUSA. "I don't know whose little girl that was, but my heart goes out to them."
A 3-month-old was among the dozens injured in a shooting that left 12 others dead in Aurora, Colorado, hospital officials said.
The identities of the victims are not yet clear.
"I saw at least four maybe five people who were limping, wounded," Milano told the affiliate. "The most that I saw was a girl that was pretty much covered in blood and she didn't have any wounds on her. It made me think the worst."
Police initially said 14 people had died, 10 in the theater and four at area hospitals, but they revised the death toll to 12 later Friday morning.
Milano said he was in the Aurora theater multiplex when the shooting took place, in a theater adjacent to theater 9 where the incident occurred.
"I saw holes in the wall," Milano said. Shots rang out and an acrid gas filled the room, he said. "I heard moaning like they were in pain."
The scene was described as chaotic by numerous movie-goers.
"There was this one guy who was on all four crawling. There was this girl spitting up blood," Donovan Tate told CNN affiliate KCNC. "There were bullet holes in some people's backs, some people's arms."
Tate said a bullet grazed his friend's neck. He said he is doing well and being treated at a nearby medical facility.
But another friend, he said, has remained unreachable.
The shooter used at least four guns -- an "AK type" rifle, a shotgun and two handguns. Police say they arrested a 24-year-old man believed to be the shooter in a rear parking lot of the theater.