All of the victims died from gunshot wounds and all were struck more than once, according to H. Wayne Carver II, chief medical examiner for the state of Connecticut. Their deaths have been 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.
He performed seven of the autopsies himself. Carver said the wounds he knew about were caused by a "long weapon." Asked by a reporter whether a rife was the primary weapon, he responded, 'Yes."
"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.
Vance said police are already talking to the one wounded adult at the school, a woman who has not been named.
"She has been treated and she'll be instrumental in this investigation, as I'm sure you can understand," he said.
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.