UPDATE Friday 12:00 p.m.
Authorities say heroes helped save lives during a deadly shooting at a New Mexico high school.
San Juan County Sheriff Ken Christesen told reporters Friday that a substitute teacher heard the gunshots Thursday morning at Aztec High School but didn't have a key to lock the door to the computer lab.
So she took students into an office or storage area and barricaded the door with a couch.
He says 21-year-old William Atchison came to the room and yelled that he knew they were in there and then fired multiple shots into the room.
Christesen says a custodian also heard the gunshots and yelled for classrooms to lock their doors.
A 21-year-old gunman who disguised himself as a student to get into a New Mexico high school where he killed two students had caught the attention of U.S. investigators more than a year ago, authorities said Friday.
William Atchison, a former student at small-town Aztec High School, had legally purchased a handgun at a local store a month ago and planned the attack, authorities said. He left a message on a thumb drive found on his body that detailed his plan to wait until the students got off buses and made their way to class.
He mingled with students, then walked into school with them and went into a second-floor bathroom to "gear up." Atchison's plan was to shoot up a classroom and then kill himself.
"Work sucks, school sucks, life sucks. I just want out of this (expletive)," he wrote.
More lives could have been lost had Francisco I. Fernandez not walked into the bathroom, authorities said. The gunman shot Fernandez, then walked out into the hallway and encountered the second victim, Casey J. Marquez. He immediately killed her.
Atchison then walked up and down the hall, firing randomly, before killing himself, authorities said.
"He was determined to create as much carnage as he possibly could," San Juan County Sheriff Ken Christesen said.
The shooter did not have a criminal record, much less a traffic ticket, officials said. The only contact with law enforcement was what they described as a generic message on an online gaming forum in 2016 in which he talked about what weapons might be used in a mass shooting.
The FBI said the posting was flagged and investigators talked with the gunman at his home in Aztec, where he lived with his parents. At the time, he did not own any weapons other than an airsoft pellet gun and said he had no plans for an attack and just liked to troll sites online.
The shooting has rocked Aztec, a community of about 6,500 near the Colorado border. Hundreds gathered for prayer services and candlelight vigils and more gatherings are planned over the weekend as residents look for answers.
In one bright spot, authorities said heroes at the school helped save lives.
A substitute teacher heard the gunshots but didn't have a key to lock the door to the computer lab. So she took students into an office or storage area and barricaded the door with a couch.
Atchison came to the room and yelled that he knew they were in there and fired multiple shots into the room, authorities said.
A custodian also heard the gunshots and yelled for teachers to lock their doors.
State Police Chief Pete Kassetas said the two victims were not specific targets.
Marquez was a cheerleader and was planning to participate in the upcoming Orange Bowl. Her classmates said she came across as a student leader.
Bryn Divine, a senior at Aztec High School, remembered the victim being a vibrant and friendly student who often won dance contests at school events.
"She lit up pretty much any room we were all in," Divine said. "She was such a fun person to be around."
Fernandez was known for his interest in computers and his speed on the keyboard. His family has said he had a bright future ahead of him.
Gov. Susana Martinez said she has met with the teens' families and they talked about what great kids they were. Both of them also had jobs.
Martinez said the families are broken but are pulling together.
"I don't think anyone ever gets over this," she said.
Investigators were still combing over evidence at the school Friday, trying to determine how many shots were fired. The gunman had several magazines and reloaded multiple times, Kassetas said.
Students hid in their classrooms, some behind locked doors or in closets, as a gunman opened fire Thursday inside a New Mexico high school, killing two classmates before he ended up dead.
Authorities and other officials in the small town of Aztec near the Colorado border have released few details other than to say the shooter and two victims attended Aztec High School.
No other injuries were reported, and it was not clear if the shooter died by suicide or was killed by police.
Bryn Divine, a senior, said she was sitting at her desk in her history class when she heard gunshots erupt down the hall. At first, it sounded as if someone was swinging a metal baseball bat against the lockers.
Then she heard an announcer over the school intercom tell students: "This is not a drill."
"I stayed in my desk, and I just prayed, 'Please just let this be over as soon as possible.' That was my first reaction," she said.
Sophomore Garrett Parker told Albuquerque television station KOAT that he also heard what he thought was banging on the lockers. Then it got louder and closer.
"Thankfully our teacher always locks the door no matter what. So he kept that locked," Parker said. "When they called over the intercom that it was not a drill, we went to the corner of the room out of sight from the door and just started hiding."
Gov. Susana Martinez called the shooting a heinous and horrific act and told reporters that teachers, school staff and law enforcement jumped in quickly to prevent more deaths. She didn't provide more details.
Police responded to the school less than a minute after getting the initial calls, which came shortly after the start of the first period. With the school in lockdown, they got inside through a window and a door.
Authorities checked each room and each building at the school before the students were bused to another location where they were reunited with their parents.
The high school remained cordoned off as the community prepared for a prayer vigil Thursday night. Aztec is a rural town of 6,500 people in the heart of northwestern New Mexico's oil and gas country and near the Navajo Nation. Its main street is lined by old brick buildings that date back more than a century.
Local, state and federal authorities said at a news conference that they had a lot of evidence to process and many interviews to conduct. They also were asking any students who might have seen something to call police.
School Superintendent Kirk Carpenter choked up, describing it as a tough day.
"At schools, our primary role and our primary job is to educate students and keep them safe, and when you have something like this, it hits you in the heart," he said.
Aztec school officials say schools across town that shut down Thursday will likely stay closed Friday.
Residents voiced disbelief on social media, while members of the New Mexico congressional delegation, state Attorney General Hector Balderas and other elected officials offered their condolences and other assistance.
UPDATED 10:25 a.m.
Authorities say three people are dead following a shooting at a New Mexico high school. San Juan County Sheriff Ken Christesen told reporters that three people believed to be students died Thursday at Aztec High School. He says the shooter also was dead but didn't say if the suspect was among the three.
Authorities said they had cleared all the buildings at the school and that students were boarding buses to another location where they could be reunited with their parents.
Deputies with the sheriff's office and surrounding police departments responded to the school after reports of a shooting. Federal agents and state police are investigating.
The school is in the Four Corners region and is near the Navajo Nation.
Authorities are responding to a shooting at a high school in northwest New Mexico.Deputies with the San Juan County Sheriff's Office told reporters that a suspect was in custody but they did not release any other information.
Sheriff Ken Christesen confirms the shooting at Aztec High School on Thursday morning. He did not say whether anyone had been injured or killed.
The school is in the Four Corners region and is near the Navajo Nation.
Authorities say the school was placed on lockdown and evacuated. Other schools in the area were also locked down, and authorities were setting up staging areas where parents could gather and wait for more information.