By Jarrett Renshaw, Gabriella Borter and Brad Brooks
UVALDE, Texas (Reuters) -President Joe Biden tried to comfort families in the south Texas town of Uvalde on Sunday after the nation's deadliest school shooting in a decade as federal officials announced they would review local law enforcement's slow response to the attack.
Anger has mounted over the decision by law enforcement agencies in Uvalde to allow the shooter to remain in a classroom for nearly an hour while officers waited in the hallway and children inside the room made panicked 911 calls for help.
The president and first lady Jill Biden wiped away tears as they visited memorials at the Robb Elementary School where the gunman killed 19 students and two teachers, laying white roses and paying respects to makeshift shrines to the victims.
"Do something," a crowd chanted outside Sacred Heart Catholic Church as Biden exited after attending mass.
"We will," he answered.
The Bidens met privately with victims' families and survivors for several hours before later meeting behind closed doors with first responders.
"We grieve with you. We pray with you. We stand with you. And we’re committed to turning this pain into action," Biden tweeted in the early evening before concluding his visit.
Police say the gunman, 18-year-old Salvador Ramos, entered the school on Tuesday with an AR-15 semi-automatic rifle after earlier shooting his grandmother, who survived.
Official accounts of how police responded to the shooting have flip-flopped wildly. The U.S. Department of Justice on Sunday said it would review the local law enforcement response at the request of Uvalde Mayor Don McLaughlin.
"I feel sorry for them because they have to live with that mistake of just standing by," Julian Moreno, a former pastor at Primera Iglesia Bautista and great-grandfather of one of the girls killed, said of Uvalde's police.
U.S. Border Patrol Chief Raul Ortiz, whose tactical officers led an assault that eventually ended the standoff at the school, defended his agency's actions.
"When my agents got the call, they rolled as quickly as they could," Ortiz told Reuters on Sunday.
The on-site commander, the chief of the school district's police department, believed the gunman was no longer an active shooter but was instead barricaded inside and that children were no longer at risk, a Texas state official said last week.
The Uvalde shooting has once again put gun control at the top of the nation's agenda, months ahead of the November midterm elections, with supporters of stronger gun laws arguing that the latest bloodshed represents a tipping point.
Biden, a Democrat, has repeatedly called for major reforms to America's gun laws but has been powerless to stop mass shootings or convince Republicans that stricter controls could stem the carnage.
'WE NEED HELP'
The Texas visit was Biden's third presidential trip to a mass shooting site, including an excursion earlier this month to Buffalo, New York, where a gunman had killed 10 Black people at a grocery store.
Texas Governor Greg Abbott, a Republican who opposes new gun restrictions, and other local officials accompanied Biden on his visit to the school on Sunday.
"We need help, Governor Abbott," some in the crowd yelled as Biden arrived. "Shame on you, Abbott."
Others shouted their thanks to Biden.
Asked if she had a message for the president, 11-year-old Bella Barboza, who was friends with one of the victims, said she was now scared to go to school and urged change.
"This world is not a good place for children to grow up in," she said.
Ben Gonzalez, a life-long Uvalde resident and father of four, was among those at the school memorial site on Sunday calling on leaders to help and saying Democrats and Republicans need to work together.
"Yes, we need new gun laws. But we also need a focus on mental health. There is not just one answer to this problem," he told Reuters.
White House aides and close allies say Biden is unlikely to wade into specific proposals or take executive action on firearms to avoid disrupting delicate negotiations in the divided Senate.
Democrats in the Senate also dialed 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's "State of the Union" program on Sunday. Durbin's fellow Democrats narrowly control the 50-50 split Senate but need 60 votes to pass most legislation.
Leading Republicans like U.S. 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.