John Larimer, a member of the Navy, was also confirmed by his family to be among the dead. The family said they were notified at their Illinois home around midnight today by a Navy notification team that Larimer was dead.
Veronica Moser, 6, was killed, according to The Associated Press. The girl's mother, Ashley Moser, 25, is in critical condition after she was shot in the throat and abdomen, said her aunt, Annie Dalton.
Oates announced Friday that Holmes had purchased four guns at local shops and more than 6,000 rounds of ammunition on the Internet in the past 60 days.
"All the ammunition he possessed, he possessed legally, all the weapons he possessed, he possessed legally, all the clips he possessed, he possessed legally," an emotional Oates told reporters.
The chief said "he could have gotten off 50 to 60 rounds, even if it was semi-automatic, within one minute," Oates said.
Eyewitness and victim accounts of the mass shooting in the packed movie theater paint a picture of panic and horror.
Eric Hunter said this morning that he was in an adjacent theater to where the shooting took place, when bullets "came right through the walls."
"When the first three shots rang out, we didn't know if it was part of the movie or not," he said. "I saw blood on the stairs and I turned to the crowd and said there's something wrong and we need to call the cops."
Hunter then said he made his way to the emergency exit door, where he saw two teen girls outside, one of whom had been hit by bullet and was asking for help. That's when Hunter said he saw the shooter.
"I saw the gunman coming around the corner so I held the door for about five seconds," Hunter said. "He's banging on the door, banging on the door... I didn't know if he was going to shoot the door. I didn't know what he had."
Holmes allegedly entered the movie auditorium wearing a ballistics helmet, bulletproof vest, bulletproof leggings, gas mask and gloves. He detonated multiple smoke bombs, and then began firing at viewers in the sold-out auditorium, police said Friday.
Holmes, who is being held in jail and will make his first court appearance Monday, is originally from Riverside, Calif., where he attended the University of California branch, Oates said Friday.
"Neighbors report that he lived alone and kept to himself," he added.
Holmes was apprehended within minutes of the 12:39 a.m. shooting at his car behind the theater, where police found him in full riot gear and carrying three weapons, including an AR-15 assault rifle, which can hold upwards of 100 rounds, a Remington 12-gauge shotgun, and a .40 Glock handgun. A fourth handgun was found in the vehicle.
Agents from the federal bureau of Alcohol, Tobacco, and Firearms are tracing the weapons.
ABC News' Brian Ross and Pierre Thomas contributed to this report.