Colorado Shooting
James Holmes, the man believed to be the alleged gunman responsible for the Colorado shooting that left 12 dead and 38 wounded in the early morning hours of Friday, July 20, is in police custody, authorities said. Twitter

Police have released the first of many 911 calls that were made in response to the shooting that took place at Century 16 Theater in Aurora, Colorado during the early hours of Friday, July 20.

In the video shown on, dispatchers can be heard releasing some of the very first details that surfaced as a result of the Colorado shooting.

They're saying somebody is shooting in the auditorium, the police dispatcher said. There is at least one person that has been shot, but they're saying there are just hundreds of people laying around, the dispatcher added.

While the phone call took place not too long after the shootings occurred, many details have since been released.

24-year-old James Holmes, a former University of Denver medical school student, has been named as the alleged gunman responsible for the shooting that left 12 dead and 38 injured.

Holmes was reportedly caught by police in the parking lot of the Century 16 Movie Theaters in Aurora, about nine miles from Denver, after dozens of 911 calls poured in around 12:39 a.m. Mountain Time. Police said it appeared to be a lone gunman, according to multiple reports.

A San Diego woman who identified herself as James Holmes' mother told ABC News she had awoken unaware of the shooting and had not yet been contacted by authorities. She immediately expressed concern that her son may have been involved.

You have the right person, she said, without elaborating. I need to call the police ... I need to fly out to Colorado.

After being obtained by police, Holmes reportedly admitted to booby-trapping his apartment with explosives. The Associated Press later confirmed that police have said the suspect's apartment is definitely booby-trapped.

The heavily armed man, with an assault rifle, a shotgun and two handguns, allegedly entered the dark theater and tossed a smoke bomb into the packed room before opening fire at a midnight showing of the Batman film.

A federal law enforcement official told CNN the smoke bomb described by witnesses was tear gas. It was unclear how the man got into the theater, but witnesses told CNN affiliate KUSA that he came in through an emergency door.

We were maybe 20 or 30 minutes into the movie and all you hear, first you smell smoke, everybody thought it was fireworks or something like that, and then you just see people dropping and the gunshots are constant, witness Christ Jones told ABC's Denver affiliate KMGH. I heard at least 20 to 30 rounds within that minute or two.

The specific theater Holmes entered was packed with movie-goers who were in the middle of viewing an early morning screening of the much-anticipated third and final installment of the Dark Knight series.

They got up and they started to run through the emergency exit, and that when she turned around, she said all she saw was the guy slowly making his way up the stairs and just firing at people, just picking random people, a man, who talked to a couple who were inside the theater, told ABC News.

The gunshot continued to go on and on and then after we didn't hear anything, the man said the couple told him. We finally got up and there was people bleeding, there was people obviously may have been actually dead or anything, and we just ran up out of there, there was chaos everywhere.

The FBI said about 100 agents are on the scene assisting with the ongoing investigation.