By JOHN CHRISTOFFERSEN and MATT APUZZO Associated Press
NEWTOWN, Conn. (AP) - The gunman in the Connecticut shooting rampage shot his mother four times in the head before going to the school and gunning down 26, authorities said Sunday as details emerged suggesting that Adam Lanza had planned an even more gruesome massacre but was stopped short.
Lanza blasted his way into the building and used a high-powered rifle to kill 20 children and six adults, including the principal who tried to stop him, authorities said.
The unthinkable bloodshed might even have been worse. Gov. Dannel Malloy said Lanza shot himself when he heard police coming. Authorities said they found multiple 30-round magazines and hundreds of bullets at the school, enough ammunition on him to carry out significant additional carnage.
"There was a lot of ammo, a lot of clips," State Police Lt. Paul Vance. "Certainly a lot of lives were potentially saved."
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 across Connecticut, 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?
Malloy offered no possible motive for the shooting and a law enforcement official has said police have found no letters or diaries left behind that could shed light on it.
Vance on Sunday officially identified Lanza as the shooter.
Lanza shot his 52-year-old mother, Nancy, to death at the home they shared Friday. She was shot four times in the head and found in her bed wearing pajamas, said a state official who was not authorized to disclose details of the investigation and spoke on condition of anonymity.
Lanza then drove to Sandy Hook Elementary School in her car with at least three of her guns, forced his way in by shooting out a window and opened fire, authorities said. Within minutes, he killed the children, six adults and himself.
Lanza had two handguns, a Glock 10 mm and a Sig Sauer 9 mm, and a Bushmaster rifle. Police also found a shotgun in his car.
All the victims at the school were shot with the rifle, at least some of them up close, and all were apparently shot more than once, Chief Medical Examiner Dr. H. Wayne Carver said. There were as many as 11 shots on the bodies he examined. Lanza died of a gunshot wound to the head from a 10 mm gun, and the bullet was recovered in a classroom wall, said the same official who described the scene at his mother's house.
All six adults killed at the school were women. Of the 20 children, eight were boys and 12 were girls.
Asked whether the children suffered, Carver said, "If so, not for very long." Asked how many bullets were fired, Carver said, "I'm lucky if I can tell you how many I found."
Parents identified the children through photos to spare them some shock, Carver said.
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," he said.
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. Obama planned to attend an interfaith vigil - the fourth time he will have traveled to a city after a mass shooting.