President Joe Biden has sought to comfort families devastated by America’s 213th mass shooting this year as the US Justice Department announced a review of the police response.
The Texas visit is Mr Biden’s third presidential trip to a shooting massacre site, including earlier this month when he visited Buffalo, New York, after a gunman killed 10 Black people in a grocery store.
Mr Biden and wife Jill, herself a teacher, laid a bouquet of flowers at the memorial at Robb Elementary in Uvalde and hugged the school’s principal Mandy Gutierrez.
They later attended Sunday mass at the Sacred Heart Catholic Church where all the pews were filled.
The Bidens will meet with victims’ families, survivors and first responders.
The Justice Department review is a significant development and was announced in response to a request from Uvalde’s mayor Don McLaughlin.
It will look closely at how law enforcement handled the country’s worst mass shooting since Sandy Hook in 2012.
It comes amid growing anger over the decision by law enforcement agencies to allow the shooter to remain in a classroom for nearly an hour while police waited in the hallway.
As children inside the building phoned 9-11 begging for help, the officers waited for a janitor to bring the keys.
Authorities have admitted it was the “wrong decision” not to storm the building sooner which parents outside the school had been desperately pleading with police do to.
“The goal of the review is to provide an independent account of law enforcement actions and responses that day, and to identify lessons learned and best practices to help first responders prepare for and respond to active shooter events,” said DOJ spokesman Anthony Coley in a statement.
“As with prior Justice Department after-action reviews of mass shootings and other critical incidents, this assessment will be fair, transparent, and independent. The Justice Department will publish a report with its findings at the conclusion of its review.”
Police say the gunman, 18-year-old Salvador Ramos, entered the school on Tuesday with an AR-15 semi-automatic rifle after earlier killing his grandmother.
Julian Moreno, a former pastor at Primera Iglesia Bautista and great-grandfather of one of the girls killed, said police made a huge error but that he felt “sorry for them because they have to live with that mistake of just standing by”.
Mr Biden was accompanied on Sunday by Texas Governor Greg Abbott, a Republican who opposes new gun restrictions, and other local officials.
“We need help, Governor Abbott,” some in the crowd yelled as Mr Biden arrived at the school.
Others shouted: “Shame on you, Abbott.”
White House aides and close allies say Mr Biden is unlikely to wade into specific policy proposals or take executive action on firearms to avoid disrupting delicate negotiations in the divided Senate.
Democrats in the Senate also dialled down the rhetoric as negotiations continued during the chamber’s Memorial Day holiday recess this week.
“We’ve got to be realistic about what we can achieve,” Senate Judiciary Chairman Dick Durbin told CNN on Sunday.
Durbin’s fellow Democrats narrowly control the 50-50 split Senate but need 60 votes to pass most legislation.
Vice President Kamala Harris called for a ban on assault-style rifles during a trip to Buffalo on Saturday, calling such firearms “a weapon of war”.
Leading Republicans like US Senator Ted Cruz of Texas, former president Donald Trump and Abbott have rejected calls for new gun control measures and instead suggested investing in mental health care or tightening school security.
Ramos, a high school dropout, had no criminal record and no history of mental illness but had posted threatening messages on social media.