Texas school shooting: Suspect's grandmother upgraded to good condition

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.

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."

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.

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.

-ABC News' Samira Said

0:41

Texas shooting survivor says gunman told them, ‘You’re all gonna die’

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

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

The response by school officials and law enforcement is becoming a key focus in the ongoing investigation into the Uvalde school shooting, law enforcement sources told ABC News Thursday.

It is unclear whether any students and teachers heard an official call for a lockdown once the gunman entered the building, the sources said.

Additionally, investigators are looking into whether officers on site could have made other attempts to enter the school to end the gunman’s rampage faster, the sources said. Responding police were met with gunfire and called for tactical teams with proper equipment to enter the classroom and neutralize the gunman, according to the sources.

-ABC News' Matt Gutman, Josh Margolin, Aaron Katersky and Luke Barr