Updated Dec. 16, 2012, 12:14 AM ET
NEWTOWN, Conn. The gunman behind the Connecticut elementary school massacre stormed into the building and shot 20 children at least twice with a high-powered rifle, executing some at close range and killing adults who tried to stop the carnage, authorities said Saturday.
He forced his way into the school by breaking a window, officials said. Asked whether the children suffered, Chief Medical Examiner Dr. H. Wayne Carver paused. "If so," he said, "not for very long."
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 and paid with her life.
The tragedy has plunged Newtown into mourning and added the picturesque New England community of handsome Colonial homes, red-brick sidewalks and 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.
Faced with the unimaginable, townspeople sadly took down some of their Christmas decorations and struggled Saturday with how to go on. Signs around town read, "Hug a teacher today," "Please pray for Newtown" and "Love will get us through."
"People in my neighborhood are feeling guilty about it being Christmas. They are taking down decorations," said Jeannie Pasacreta, a psychologist who was advising parents struggling with how to talk to their children.
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."
The tragedy brought forth soul-searching and grief around the globe. President Barack Obama planned to visit Newtown on Sunday. Families as far away as Puerto Rico planned funerals for victims who still had their baby teeth, world leaders extended condolences, and vigils were held around the U.S.
"Next week is going to be horrible," said the town's legislative council chairman, Jeff Capeci, thinking about the string of funerals the town will face. "Horrible, and the week leading into Christmas."
Police shed no light on what triggered Adam Lanza, 20, to carry out 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 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.
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 in and opened fire, authorities said. Within minutes, he killed 20 children, six adults and himself.
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 Friday.
A nurse who had been with the school for 15 years, told CBS News' Scott Pelley that no one knows Nancy Lanza and that she was not a staff teacher, after earlier reports said Nancy Lanza worked at the school. The nurse said its conceivable that Nancy Lanza was a substitute that she never met, but very unlikely. No other staff member the nurse has talked to has ever heard of Nancy Lanza. The nurse also knows of no connection between the shooter and the school.
CBS News correspondent John Miller reported on what happened when Adam Lanza was inside the school during the shooting: The first police officer on the scene was confronted by the glass window that Lanza had shot his way through to get past the locked door. The officer advanced into the school and saw the gunman, from a great distance down a long hallway, perhaps a couple of hundred feet. The gunman, dressed all in black, spotted the officer and ducked into a room off the hallway.
As the officer, now joined by a partner began to rush down the hall toward the gunman they heard a volley of shots. When they got there, they found the gunman, dead from a self-inflicted gunshot wound. Just beyond the gunman, in a classroom, children huddled together, and their teacher, all of them shot multiple times. Nearby, in a bathroom another group of children, huddled together, all shot multiple times. As the officers ran down the hallway, they heard several shots. It appears that the gunman let go a last volley of shots at his victims before killing himself with a single bullet to the head.
There is an unconfirmed report that Lanza was involved in an altercation with school staffers the day before the shooting. Miller spoke to a law enforcement source regarding that report. The source said what they are focused on was there was some kind of argument between people in the office, and the people in the office of that school are dead. The source said the key is to figure out if Lanza was part of that, present for it or somehow involved. Additionally, the source said right now they have any indication Lanza was, but he said they have to run that out it make sure.
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, 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.