DENVER (KDVR) — The student who opened fire at Evergreen High School on Wednesday has been identified as 16-year-old Desmond Holly, the Jefferson County Sheriff’s Office announced Thursday.

Calls flooded in to 911 when the shooting happened at 12:24 p.m. on Wednesday, both inside and outside of the school. Three people were injured, including Holly, who died of a self-inflicted gunshot wound at a hospital on Wednesday evening, according to the sheriff’s office.

A spokesperson for the St. Anthony Hospital had previously said that one victim was released from the hospital, but during a press conference Thursday morning, the sheriff’s office clarified that the two other victims remain in hospital care. A spokesperson for Children’s Hospital Colorado confirmed to FOX31 that one victim was transferred there and remains in critical condition.

The sheriff’s office said the victims’ families plan to release their identities and a statement soon. One of the victims was identified on Thursday as 18-year-old Matthew Silverstone.

New details on Evergreen High School shooting investigation

The investigation remains ongoing, but a spokesperson for the sheriff’s office released some details about the investigation during the press conference.

There were multiple crime scenes, some inside and some outside but all on school property. Investigators now know that one of the crime scenes spilled over onto the roadway behind the school. The spokesperson said one person was shot inside, and another was shot outside.

The gun used was a revolver handgun of an unknown caliber.

Holly also brought “quite a bit” of ammunition and continued to reload, the spokesperson said, adding that investigators are thankful that there were not more injuries. She said that the suspect’s gun was fired “a lot,” but the exact number of rounds is unknown.

Security cameras inside the school captured the entire incident, which investigators are using to track Holly’s movement throughout the school. Some kids were at lunch at the time of the shooting, so some were in the halls and outside. Some of the kids ran away from the gunfire, while others locked down.

“It was just chaos and I don’t think that’s avoidable when you have something like this ever,” the spokesperson said.

Holly tried to access areas that were locked down but could not enter. The spokesperson said that students and teachers did their job in the lockdown, which kept them safe and likely saved lives.

One student told FOX31’s Courtney Fromm on Wednesday that he was in the school’s band room when the lockdown began. He said the students “kind of freaked out” after hearing two gunshots and they hid in a corner. He said he felt some kind of debris hit his forehead before he and other students crawled into the band director’s office, where they hid for over an hour.

“I saw him right in front of me and everything, and he was on the other side of the room in the door, and I saw the gun and everything pointed at me and everybody else … and it’s just … it was something. I think he broke the window and tried to get through, but I don’t think he did. I think they went past our room they just kind of gave up,” the student said.

Inside the building, investigators have found lockers and windows that were struck by the gunfire and continue to find spent and unspent rounds. The spokesperson noted that the school is three levels and there is a lot of area to cover in the investigation.

The sheriff’s office previously reported that a fourth person was taken to a hospital after they were injured while fleeing from the incident, but the spokesperson said they no longer believe that to be true.

School resource officer dispatched elsewhere before shooting

The school used to have a full-time school resource officer; however, they are currently on medical leave. In the meantime, a couple of part-time Jefferson County deputy school resource officers are sharing that school.

There was no one from the school resource officer unit at the school at the time of the shooting, and the spokesperson said he was there until about 10:30 a.m. but left when he was dispatched for a crash nearby. The spokesperson clarified that he followed protocol.

The spokesperson said they have no reason to believe that Holly waited for the officer to leave before opening fire.

Investigation into the shooter

Deputies responded and contacted the shooter within about five minutes, and the spokesperson said they may be able to release more details about that encounter at a later time.

The sheriff’s office has warrants secured for Holly’s home, phone and locker, and they are in close contact with his family. He did not bring a car and rode the bus to school on Wednesday morning, the spokesperson said.

Investigators are trying to learn how Holly came into possession of the gun, and it is unknown how he concealed it ahead of the shooting.

The sheriff’s office said that investigators cannot say whether the shooting was targeted or random, but based on evidence of hit firing and reloading, “it could be a bit of both.”

Investigators have been to the shooter’s home, and the spokesperson said she does not know what they found there but believes it was valuable information for the case.

Investigators are looking into a motive but do not have one yet. However, the spokesperson said that so far into the investigation, there is information indicating that the shooter was “radicalized through an extremist network.” She said more information on that will be released at a later time.

“There’s some level of confirmation that there’s something we really need to take a deeper look at,” the spokesperson said.

The spokesperson also said the sheriff’s office is looking into possible charges related to his access to the weapon.

When asked if they had heard from other students concerned about the shooter’s behavior, the spokesperson said she was unaware of any warnings about this.

“I have to believe when you bring a gun to school and you continue to fire and reload, and fire and reload, that you are on a mission, and we’re grateful that he was less successful but we’re devastated that he was successful at all,” the spokesperson said.

Holly’s autopsy was completed on Thursday morning, and the investigation is ongoing.