"He just started unloading pretty much the whole clip," said Sam Nathavong, who told CNN affiliate KRQE that he was in a room studying when he heard the shots.
"I threw the table against the door and I barricaded myself in there," Nathavong said. "I thought he was coming my way and by then the cops got there."
As gunfire erupted at the Clovis-Carver Public Library just after 4 p.m. local time, police arrived to the scene to confront the shooter inside the library.
The gunman was arrested without firing anymore shots, according to police.
"He gave up. He didn't resist," Clovis Police Chief Douglas Ford said at a news conference.
Police arrested high-schooler Nathaniel Jouett, 16, who is expected to face first-degree murder charges.
Prosecutors said Tuesday they intend to seek adult criminal charges against Jouett, who they say shot and killed two library employees, Wanda Walters, 61, and Kristina Carter, 48. Three adults and a 10-year-old child were also wounded.
Girlfiriend: Suspect was distraught over bullying
Davena Stevens, Jouett's 16-year-old girlfriend, told CNN that Jouett was distraught over what she described as a bullying incident at school on Friday. Police Chief Doug Ford said that incident, which led to Jouett's suspension, is part of the investigation.
Jouett has not commented on the allegations. He will appear in juvenile court later this week.
Stevens said she received a Snapchat from Jouett the afternoon of the shooting, saying he would be over to her house at 4:30 p.m. But when news of the shooting hit, and Jouett was nowhere to be found, she rushed over to the Jouett house.
"They said two of his dad's guns were missing, and right then I knew it was probably him," Stevens said.
Police wouldn't confirm where the guns used in the crime came from, saying that's part of the investigation.
The victims remembered
On Tuesday night, community members gathered at a church to pray and remember the victims.
Walters had worked as a circulation assistant at the library.
"She cares about the people who come in here," said Nathan Pruett, a Clovis resident who frequented the library and was fond of Walters.
"She prayed for me and my mom who had a stroke," Pruett said. "And now I'm here praying for her family."
Carter worked in youth services at the library. Her family told KRQE
that she loved working at the library and reading to kids.
"I've heard so many wonderful stories about them, please keep them in your thoughts and prayers," said Gov. Susana Martinez, who visited the four wounded victims recovering at a Lubbock, Texas, hospital.
Clovis mayor David Lansford called the shooting "such a senseless tragedy, and there isn't a reason for it."
"When it's all said and done you can come up with a lot of explanations, but I don't anyone will ever be able to put a reason on why these kinds of things happen."
Clovis, a city with an estimated population of 40,000, boasts itself as the home of Cannon Air Force Base. The city is about 200 miles east of Albuquerque and is an agricultural and rail hub on the New Mexico-Texas state line.
Who is the teenage suspect?
Last month, Jouett stood over a podium, sobbing as he told a congregation about his life during an evening church service at the Living Word Church of God, where Jouett had attended.
"I hit rock bottom, and the only good thing about hitting rock bottom is you can only go up," Jouett said to a chorus of "Amens."
"Let it out," one member of the congregation said during Jouett's roughly half-hour testimonial. A video of it was made available to CNN by the church.
Much of it centers on Jouett's estrangement from his biological mother.
"I was really sad," he told the congregation, of the period when they first became estranged. "I took a knife up and down my chest," he said.
Jouett rediscovered church life about four months ago and had recently been baptized, his girlfriend said.
"How do you go from getting baptized to shooting up a place?" Davena Stephens said Tuesday.
Jouett's father, Chris, and his stepmother spoke briefly to CNN on Tuesday outside the Clovis Police Department. They declined to comment publicly.
Associate Pastor Paula Stevens, whose daughter, Davena, is dating Jouett, said of the alleged crime, "I'm not minimizing what he did. What he did was terrible and lives are forever destroyed. I just want people to know... he's a hurting young kid who was at his breaking point."
"I think we didn't have enough time," she said. "And somewhere along the way we missed something."