Newtown, Connecticut (CNN) -- Authorities in Newtown, Connecticut, put together more pieces of the puzzle Saturday to explain what happened inside Sandy Hook Elementary School, one day after a gunman opened fire there, killing 20 students and six adults.
All the victims died from gunshot wounds and were struck more than once, according to H. Wayne Carver II, chief medical examiner for the state of Connecticut. Their deaths were classified as homicides.
"I've been at this for a third of a century. My sensibilities may not be the average man, but this probably is the worst I have seen or the worst that I know of any of my colleagues having seen," Carver told reporters.
The deadly school shooting shattered the quiet of this southern New England town and left a nation reeling over the number of lives, particularly young lives lost. It also reignited the perennial debate about gun laws in America.
President Barack Obama spoke tearfully about the massacre on Friday and is scheduled to travel to Newtown on Sunday to meet with families of the victims. He will deliver remarks during an evening vigil.
Law enforcement officials have identified the gunman as 20-year-old Adam Lanza. He apparently took his own life, after taking that of his mother and the 26 people at the school.
Lanza was found dead next to three guns, a semi-automatic .223-caliber Bushmaster rifle and two pistols made by Glock and Sig Sauer, a law enforcement source told CNN. All belonged to his mother.
Carver, who performed autopsies on seven of the victims, said the wounds he knew about were caused by a "long weapon." Asked by a reporter whether the rifle was the primary weapon, he responded, "Yes."
He spoke as police released a list of the names of ages of the victims. Twelve girls and eight boys were killed, all either 6 or 7 years old. The adults ranged in ages from 27 to 56, and included the school's principal, psychologist and at least two teachers.
Among those killed was Emilie Parker, 6.
"As the deep pain begins to settle into our hearts, we find comfort reflecting on the incredible person that Emilie was and how many lives that she was able to touch in her short time here on Earth," her father, Robbie Parker, told reporters, struggling to speak through tears.
He described his daughter as bright, creative and loving. She loved to draw pictures and try new things.
"Emilie's laughter was infectious and all those who had the pleasure to meet her would agree that this world is a better place because she has been in it," her father said.
Also killed were Dawn Hochsprung, the school's beloved principal, school psychologist Mary Sherlach, Vicki Soto, a first-grade teacher, and substitute teacher Lauren Rousseau.
Searching for answers in their deaths, major crime investigators police were combing "every crack and crevice" of the school.
They said they're finding some "very good evidence" there, and at the home of the shooter. Lanza's mother, Nancy, was killed at that house, authorities said.
"The detectives will certainly analyze everything and put a complete picture together of the evidence that they did obtain, and we're hopeful -- we're hopeful -- that it will paint a complete picture as to how and why this entire unfortunate incidence occurred," said Lt. J. Paul Vance, a spokesman for the Connecticut State Police.
Authorities, meanwhile, in Hoboken, New Jersey, were questioning Ryan Lanza, the suspected gunman's older brother, law enforcement sources said, though they did not label him a suspect. Lanza's father, Peter, who lives in Connecticut, was similarly questioned, one of the law enforcement officials said.
Peter Lanza released a statement Saturday expressing condolences to the families of victims.
"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. We are in a state of disbelief and trying to find whatever answers we can," said the statement.
Two law enforcement sources said Adam Lanza lived with his mother. Contrary to early reports, they said, Nancy Lanza was not a teacher at Sandy Hook Elementary.
Nancy Lanza was a gun collector and recently showed off a newly bought rifle to fellow Newtown resident Dan Holmes, who owns a landscaping business in the town.
Besides the three weapons found at the school, Adam Lanza also had access to at least three more guns, a law enforcement source said. Investigators recovered a .45-caliber Henry Repeating Rifle, a .22-caliber Marlin Rifle and a .30-caliber Enfield Rifle, though it's unclear where they were found, the source said.
Investigators believe Lanza killed his mother and then took her guns and made his way to the elementary school wearing black fatigues and a military vest, according to a law enforcement official.
According to Vance, Lanza forced his way into the school though he wouldn't say how or whether Lanza used weapons to do it.
Authorities said it's also not clear whether Lanza entered before or after 9:30 a.m., the time each day when the school would lock its doors as part of a security system introduced this year. Authorities say the first emergency call about the shooting came in at "approximately" 9:30 a.m. Friday.
Within minutes, 26 people had been killed with chilling efficiency, leaving only the one wounded survivor. The survivor, an adult, has not been named.
"She has been treated and she'll be instrumental in this investigation, as I'm sure you can understand," Vance said.
The massacre in Newtown is the second-deadliest school shooting in U.S. history, behind the 2007 Virginia Tech mass shooting that left 32 dead.
"Stuff like this does not happen in Newtown," said Renee Burn, a teacher at another school in the town, which is roughly 75 miles northeast of New York City.
Until Friday, only one homicide in the past 10 years had been reported in the upscale community of expansive homes surrounded by woods, where many residents commute to jobs in Manhattan and the nearby Connecticut cities of Stamford and Hartford.
Flags were lowered to half-staff in a number of states, and vigils were held at houses of worship and at schools amid a national outpouring of grief.
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CNN's Susan Candiotti and David Ariosto reported from Newtown, Connecticut; Dana Ford from Atlanta. CNN's Chelsea J. Carter, Sarah Aarthun, Meredith Artley, John King, Ashleigh Banfield, Joe Johns, Terry Frieden and Michael Martinez contributed to this report.