NEWTOWN, Conn. - Investigators tried to figure out what led a bright but painfully awkward 20-year-old to slaughter 26 children and adults at a Connecticut elementary school, while townspeople sadly took down some of their Christmas decorations and struggled Saturday with how to go on.
The tragedy brought forth soul-searching and grief around the globe. Families as far away as Puerto Rico began to plan funerals for victims who still had their baby teeth, world leaders extended condolences, and vigils were held around the United States.
The White House announced that President Obama would attend an interfaith memorial service Sunday in Newtown.
Relatives of the shooter, whose victims included his mother, were at a loss for words.
"The whole family is traumatized by this event," said a police official who knows the family.
A family statement read: "We reach out to the community of Newtown and express our heartfelt sorrow for this incomprehensible and profound loss of innocence."
Amid the sorrow, stories of heroism emerged, including an account of the Sandy Hook Elementary School principal and the school psychologist who lost their lives rushing toward the gunman, Adam Lanza, in an attempt to stop him.
Police shed no light on what triggered the second-deadliest school shooting in U.S. history, though State Police Lt. Paul Vance said investigators had found "very good evidence ... that our investigators will be able to use in painting the complete picture, the how and, more importantly, the why." He would not elaborate.
However, another law enforcement official, speaking on condition of anonymity, said investigators had 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 in which a gunman killed 32 people.
The mystery deepened as Newtown 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 Elementary many years ago, but they had no explanation for why he went there on Friday.
Lanza shot to death his mother, Nancy Lanza, at the home they shared, then drove to the school in her car with at least three of her guns, forced his way inside and opened fire in two classrooms, authorities said. Within minutes, he killed 20 children, six adults, and himself.
On Saturday, Chief Medical Examiner H. Wayne Carver said all the victims at the school were shot with a rifle, at least some of them up close, and all of them were apparently shot more than once. All six adults killed at the school were women. Of the 20 children, eight were boys and 12 were girls. All the children were 6 or 7 years old.
Asked how many bullets were fired, Carver said: "I'm lucky if I can tell you how many I found."
The list of the dead was released Saturday, but in the tightly knit town, nearly everyone already seemed to know someone who died.
Among the dead: well-liked principal Dawn Hochsprung, 47, who town officials say tried to stop the rampage; school psychologist Mary Sherlach, 56, who probably would have helped survivors grapple with the tragedy; a teacher thrilled to have been hired this year; and a 6-year-old girl who had just moved to Newtown from Canada.
"Next week is going to be horrible," said the town's legislative council chairman, Jeff Capeci, thinking about the string of funerals ahead. "Horrible, and the week leading into Christmas."
School board chairwoman Debbie Leidlein spent Friday night meeting with parents who lost children and shivered as she recalled those conversations. "They were asking why. They can't wrap their minds around it. Why? What's going on?" she said. "And we just don't have any answers for them."
Hours after the shooting, a tearful Obama said he grieved first as a father. In those remarks and later in his Saturday radio address, Obama called for "meaningful action" to prevent such shootings, but did not say what it should be.
Obama's visit to Newtown for an interfaith vigil would be the fourth time he has traveled to a city after a mass shooting.
The president had planned to travel to Maine on Wednesday for an event promoting his positions in fiscal cliff negotiations, but the White House canceled that trip because of the shooting.
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 had been diagnosed with Asperger's syndrome, 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.
Acquaintances describe the former honors student as smart but odd and remote.
Olivia DeVivo, now a student at the University of Connecticut, recalled that Lanza always came to school toting a briefcase and wearing his shirt buttoned all the way up. "He was very different and very shy and didn't make an effort to interact with anybody" in his 10th-grade English class, she said.
"You had yourself a very scared young boy who was very nervous around people," said Richard Novia, who was the school district's head of security and adviser to the high school's Tech Club, of which Lanza was a member. He added: "He was a loner."
When people approached Lanza in the hallways, he would press himself against the wall or walk in a different direction, clutching his black case "like an 8-year-old who refuses to give up his teddy bear," said Novia, who now lives in Tennessee.
Lanza's family was struggling to make sense of what happened and "trying to find whatever answers we can," his father, Peter Lanza, said in a statement late Saturday that also expressed sympathy for the victims' families.
Sandy Hook Elementary will be closed this week - some parents can't even conceive of sending their children back, Leidlein said - and officials are deciding what to do about the town's other schools.
Asked whether the town would recover, Maryann Jacob, a clerk in the school library who took cover in a storage room with 18 fourth graders during the shooting rampage, said: "We have to. We have a lot of children left."