President Barack Obama is vowing to use "whatever power this office holds" to safeguard the nation's children, raising the prospect that he will pursue policy changes to stem gun violence in the wake of an elementary school massacre.
"Because what choice do we have?" a somber Obama said at a Sunday evening vigil in the grieving community of Newtown, Conn. "We can't accept events like this as routine. Are we really prepared to say that we're powerless in the face of such carnage? That the politics are too hard?"
The newly re-elected president offered few specifics about how he planned to proceed, saying only that he will engage with law enforcement, mental health professionals, parents and educators in the coming weeks. Just days after the shooting at an elementary school, Obama is already facing pressure from fellow Democrats and New York City Mayor Michael Bloomberg to tackle gun control legislation, a contentious issue he avoided as he sought a second term.
But Friday's shooting, which left 20 children and eight adults dead, appears to have spurred some soul-searching by Obama, who told Connecticut's governor that Friday was the most difficult day of his presidency. Speaking to families of the victims and first responders, Obama said Sunday that he had been reflecting on whether the country was doing enough to give its children "the chance they deserve to live out their lives in happiness and with purpose."
"And if we're honest with ourselves, the answer is no. We're not doing enough, and we will have to change," Obama said.
Sunday marked the fourth time in Obama's presidency that he has traveled to a community shaken by a mass shooting. Just this summer, he made a similar visit to Aurora, Colo., where a dozen people were killed in a movie theater attack.
Drawing on his past experiences, Obama said he was mindful that mere words would not be enough to heal the depths of Newtown's sorrow.
"I can only hope that it helps for you to know that you are not alone in your grief," Obama said during the vigil, which followed his private meeting with families of the victims.
The president closed his remarks by reading the first names of the kids, slowly, in the most wrenching moment of the night. Cries and sobs filled the room.
Said Obama of the girls and boys who died: "God has called them all home. For those of us who remain, let us find the strength to carry on and make our country worthy of their memory."
Inside the room, children held stuffed teddy bears and dogs. The smallest kids sat on their parents' laps.
There were tears and hugs, but also smiles and squeezed arms. Mixed with disbelief was a sense of a community reacquainting itself all at once.
One man said it was less mournful, more familial. Some kids chatted easily with their friends. The adults embraced each other in support.
"We're halfway between grief and hope," said Curt Brantl, whose daughter was in the library of the elementary school when the shootings occurred. She was not harmed.
Police and firefighters got hugs and standing ovations when they entered. So did Obama.
"We needed this," said the Rev. Matt Crebbin, senior minister of the Newtown Congregational Church. "We needed to be together to show that we are together and united."
The shootings have restarted a debate in Washington about what politicians can to do help - gun control or otherwise. Obama has called for "meaningful action" to prevent killings.
Police said the gunman, Adam Lanza, was carrying an arsenal of ammunition big enough to kill just about every student in the school if given enough time. He massacred 20 students and six teachers and administrators before shooting himself in the head just as he heard police drawing near, authorities said.
A Connecticut official said the gunman's mother was found dead in her pajamas in bed, shot four times in the head with a.22-caliber rifle. The killer then went to the school with guns he took from his mother and began blasting his way through the building.
"There is no blame to be laid on us, but there is a great burden and a great challenge that we emerge whole," First Select Woman Patricia Llodra said. "It is a defining moment for our town, but it does not define us."
Latest on the investigation
In the last press conference of the day Sunday, Connecticut State Police confirmed which gun the shooter, Adam Lanza, used to commit most of the murders at Sandy Hook Elementary.
Police said Lanza used a Bushmaster .223-caliber assault-type weapon with a high capacity magazine. All the weapons used had multiple magazines with about 30 rounds per magazine.
Officials are still unsure how many shots were fired, though they indicated that Lanza had hundreds of rounds on him. There was also a shotgun found in Lanza's vehicle outside of the school.
There was a bomb threat at a church in Newtown, police said. The church was evacuated and searched.
Police also confirmed Nancy Lanza, 52, has been positively identified and her death is classified as homicide by gunshot.
Earlier, the governor said Lanza committed suicide as first responders closed in, raising the specter that Adam Lanza had planned an even more gruesome massacre and was stopped short.
Lanza blasted his way into the building and used a high-power rifle to kill 20 children and six adults, including the principal who tried to stop him, authorities said.
As President Barack Obama prepared a visit and churches opened their doors to comfort a grieving town Sunday, federal agents fanned out to dozens of gun stores and shooting ranges, chasing leads they hoped would cast light on Lanza's life.
Among the questions: Why did his mother, a well-to-do suburban divorcee, keep a cache of high-power weapons in the house? What experience did Lanza have with those guns?
And, above all, what set him on a path to go classroom-by-classroom, massacring 6- and 7-year-olds?
Learning about the victims
The terrible details about the last moments of young innocents emerged as authorities released their names and ages — the youngest 6 and 7, the oldest 56. They included Ana Marquez-Greene, a little girl who had just moved to Newtown from Canada; Victoria Soto, a 27-year-old teacher who apparently died while trying to hide her pupils; and principal Dawn Hochsprung, who authorities said lunged at the gunman in an attempt to overtake him.
The tragedy has plunged Newtown into mourning and added the picturesque New England community of 27,000 people to the grim map of towns where mass shootings in recent years have periodically reignited the national debate over gun control but led to little change.
School officials were trying to determine what to do about sending the survivors back to class, Newtown police Lt. George Sinko said at a news conference Sunday.
Sinko said he "would find it very difficult" for students to return to the school. But, he added, "we want to keep these kids together. They need to support each other."
Plans were being made for some students to attend classes in nearby Monroe, said Jim Agostine, superintendent of schools there.
Residents and faith leaders reflected Sunday on the mass shooting and what meaning, if any, to find in it.
At St. Rose of Lima Roman Catholic Church, Jennifer Waters, who at 6 is the same age as many of the victims and attends a different school, came to Mass on Sunday in Newtown with a lot of questions.
"The little children — are they with the angels?" she asked her mother while fiddling with a small plastic figurine on a pew near the back of the church. "Are they going to live with the angels?"
Her mother, Joan, 45, assured her they were, then put a finger to her daughter's lips, urging her to be quiet.
An overflow crowd of more than 800 people attended the 9 a.m. service at the church, where eight children will be buried later this week. The gunman, Adam Lanza, and his mother also attended church here. Spokesman Brian Wallace said the diocese has yet to be asked to provide funerals for either.
Boxes of tissues were placed strategically in each pew and on each window sill. The altar was adorned with bouquets, one shaped as a broken heart, with a zigzag of red carnations cutting through the white ones.
In his homily, the Rev. Jerald Doyle, the diocesan administrator, tried to answer the question of how parishioners could find joy in the holiday season with so much sorrow surrounding them.
"You won't remember what I say, and it will become unimportant," he said. "But you will really hear deep down that word that will finally and ultimately bring peace and joy. That is the word by which we live. That is the word by which we hope. That is the word by which we love."
After the Mass, Joan and Jennifer stopped by a makeshift memorial outside the church, which was filled with votive candles and had a pile of bouquets and stuffed animals underneath, to pray the Lord's Prayer.
Jennifer asked whether she could take one.
"No, those are for the little children," her mother replied.
"Who died?" her daughter asked.
"Yes," said her mother, wiping away a tear.
Amid the confusion and sorrow, stories of heroism emerged, including an account of Hochsprung, 47, and the school psychologist, Mary Sherlach, 56, rushing toward Lanza in an attempt to stop him. Both died.
There was also 27-year-old teacher Victoria Soto, whose name has been invoked as a portrait of selflessness. Investigators told relatives she was killed while shielding her first-graders from danger. She reportedly hid some students in a bathroom or closet, ensuring they were safe, a cousin, Jim Wiltsie, told ABC News.
"She put those children first. That's all she ever talked about," a friend, Andrea Crowell, told The Associated Press. "She wanted to do her best for them, to teach them something new every day."
There was also 6-year-old Emilie Parker, whose grieving father, Robbie, talked to reporters not long after police released the names of the victims but expressed no animosity, offering sympathy for Lanza's family.
"I can't imagine how hard this experience must be for you," he said.
Lanza's family grieves, apologizes
The gunman's father, Peter Lanza, issued a statement relating his own family's anguish in the aftermath.
"Our family is grieving along with all those who have been affected by this enormous tragedy. No words can truly express how heartbroken we are," he said. "We are in a state of disbelief and trying to find whatever answers we can. We too are asking why. ... Like so many of you, we are saddened, but struggling to make sense of what has transpired."
The rifle used was a Bushmaster .223-caliber, according to an official with knowledge of the investigation who was not authorized to speak about it and talked on condition of anonymity. The gun is commonly seen at competitions and was the type used in the 2002 sniper killings in the Washington, D.C., area. Also found in the school were two handguns, a Glock 10 mm and a Sig Sauer 9 mm.
A law enforcement official said Saturday that authorities were investigating fresh leads that could reveal more about the lead-up to the shooting. The official spoke on condition of anonymity because he was not authorized to discuss the matter publicly.
Ginger Colbrun, spokeswoman for the Bureau of Alcohol, Tobacco, Firearms and Explosives, said earlier there was no evidence Lanza was involved in gun clubs or had trained for the shooting. When reached later in the day and asked whether that was still true, she said, "We're following any and all leads related to this individual and firearms."
Law enforcement officials have said they have found no note or manifesto from Lanza of the sort they have come to expect after murderous rampages such as the Virginia Tech bloodbath in 2007 that left 33 people dead.
Education officials said they had found no link between Lanza's mother and the school, contrary to news reports that said she was a teacher there. Investigators said they believe Adam Lanza attended Sandy Hook many years ago, but they had no explanation for why he went there Friday.
Authorities said Adam Lanza had no criminal history, and it was not clear whether he had a job. Lanza was believed to have suffered from a personality disorder, said a law enforcement official who spoke on condition of anonymity.
Another law enforcement official, also speaking on condition of anonymity, said Lanza also had been diagnosed with Asperger's, a mild form of autism often characterized by social awkwardness.
People with the disorder are often highly intelligent. While they can become frustrated more easily, there is no evidence of a link between Asperger's and violent behavior, experts say.
The law enforcement officials insisted on anonymity because they were not authorized to discuss the unfolding investigation.
Richard Novia, the school district's head of security until 2008, who also served as adviser for the high school technology club, of which Lanza was a member, said he clearly "had some disabilities."
"If that boy would've burned himself, he would not have known it or felt it physically," Novia said in a phone interview. "It was my job to pay close attention to that."
Information from the Associated Press was included in this report.