The alleged gunman -- identified by authorities as 18-year-old Salvador Ramos, a student at Uvalde High School -- was killed by law enforcement at the scene.
The suspect allegedly shot and injured his grandmother before opening fire at the school, officials said.
Officers did not breach classroom for 35 minutes while shooter was inside
Steven McCraw, director of Texas Department of Public Safety, admitted it was the "wrong decision" for officers not to go into the classroom where the suspect was for 35 minutes after a tactical unit arrived. Children were inside the classroom with him, making 911 calls, McCraw said in a press conference Friday.
The incident commander believed he was dealing with a barricaded subject inside the school and the children were not at risk, he said.
A tactical team from Customs and Border Protection was on scene at 12:15 p.m., but did not breach the classroom until 12:50 p.m.
"Of course it wasn't the right decision," McCraw said. "It was the wrong decision."
2:18
Texas shooting 911 calls detail horror of rampage
Authorities in Texas provide an update on the shooting at Robb Elementary School that killed 19 children and two teachers.
ABCNews.com
May 27, 2022, 11:23 AM EDT
US Marshals say they never arrested or handcuffed anyone outside school
The U.S. Marshals said they never placed anyone in handcuffs, but they say they “maintained order and peace in the midst of the grief-stricken community that was gathering around the school," in a statement posted on Twitter.
U.S. Marshals arrived on scene from Del Rio, Texas, at 12:10 p.m., and the first deputy U.S. Marshal went into the school to assist BORTAC, the elite tactical CBP team that ultimately shot the alleged shooter, the statement said.
People embrace at a memorial in the town square for victims of Tuesday's mass shooting at Robb Elementary School on May 26, 2022 in Uvalde, Texas.
Eric Thayer/Getty Images
They came from 70 miles away and got the first call around 11:30 a.m., according to the statement.
“These Deputy US Marshals also rendered emergency trauma first aid for multiple victims,” the statement said.
"Additional Deputy U.S. Marshals were asked to expand and secure the official law enforcement perimeter around the school,” the statement said. “Our hearts are heavy with sorrow and sadness at this horrific crime. We send our condolences to all the victims and families affected by this tragedy."
People visit a memorial for victims of Tuesday's mass shooting at a Texas elementary school, in the town Square on May 26, 2022 in Uvalde, Texas.
Michael M. Santiago/Getty Images
Angeli Rose Gomez, a mother waiting outside for her children, told the Wall Street Journal she was one of numerous parents urging police and law enforcement officers to go into the school sooner, first politely and then more urgently. She said U.S. Marshals put her in handcuffs, and told her she was being arrested for intervening in an active investigation.
Angel Garza, the stepfather of one of the children killed in the shooting, ran to try to reach and help his child, and was restrained and handcuffed by a local police officer, Desirae Garza, the girl's aunt, recounted to the New York Times.
May 27, 2022, 6:30 AM EDT
10-year-old survivor recalls gunman saying: 'You're all gonna die'
There was blood in the hallway and children were covered in it, one of the students who survived the mass shooting at Robb Elementary School in Uvalde, Texas, told ABC News.
Samuel Salinas was a student in Irma Garcia's fourth grade class. They were scheduled to graduate Thursday, but the ceremony was canceled because Garcia, another teacher and 19 third and fourth grade students were killed in Tuesday's massacre.
Salinas said his aunt dropped him off for school on Tuesday morning.
"It was a normal day until my teacher said we're on severe lockdown," he told ABC News, "and then there was shooting in the windows."
Salinas said the gunman came into his classroom, closed the door and told them, "You're all going to die," before opening fire.
"He shot the teacher and then he shot the kids," Salinas said, recalling the cries and yells of students around him.
Samuel Salinas, 10, a student at Robb Elementary School, details the shooting that claimed the lives of his teacher and some of his classmates.
ABCNews.com
May 26, 2022, 9:57 PM EDT
Accused shooter's mother at one point worked at same establishment of gun purchase: Sources
Sources told ABC News the accused school shooter’s mother, Adriana Reyes, at one point worked at Oasis Outback, the same store where the gunman purchased two weapons just after his 18th birthday earlier this month.
The establishment is half gun retailer, half restaurant; Reyes’ employment was with the restaurant portion, sources say.
It is unclear if she had any role in her son’s purchase of the firearms. The owner of Oasis declined to comment to ABC News and added he would only speak with law enforcement at this time. Reyes has not responded to ABC News’ request for comment.
-ABC News' Matt Gutman, Laura Romero and Victor Ordonez
