State police spokesman Lt. J. Paul Vance said it is too soon to draw any conclusions. A final report on the investigation could be months away.
Lanza destroyed the hard drive of his computer before the attack, and investigators have been unable to retrieve any information from it, according to a person briefed on the case.
And while they haven't given up, they aren't confident they will be able to repair it, the person said, speaking on condition of anonymity because he was not authorized to discuss the case publicly.
In Newtown, the community endured another mournful, overcast day filled with multiple funerals and visitations. At the hour of the attack, 9:30 a.m., a bell tolled 26 times, once for each victim killed at the school.
Gov. Dannel P. Malloy gathered with other officials in rain and wind on the steps of the Edmond Town Hall as the bell rang. Officials didn't make any formal remarks, and similar commemorations took place throughout the country.
Also on Friday, the National Rifle Association spoke out for the first time since the shootings, calling for armed police officers to be stationed at schools to stop the next killer "waiting in the wings."
Wayne LaPierre, CEO of the nation's largest gun-rights lobbing group, said at a Washington news conference that "the only thing that stops a bad guy with a gun is a good guy with a gun."
LaPierre blamed video games, music and videos for exposing children to violence.
At the memorial services, a school psychologist who rushed toward the gunman was remembered as a caring professional, a passionate fan of the Miami Dolphins and a woman who ultimately put the lives of others ahead of her own.
One of Mary Sherlach's friends donned a Dan Marino jersey for her funeral, which drew a standing-room-only crowd to St. Stephen Roman Catholic Church in Trumbull.
The church was adorned with a Christmas tree and several wreaths, including one with the teal, white and orange colors of the Dolphins.
Rev. Stephen Gleason said Sherlach's love was Christ-like.
"No one has greater love than to give one's life for his friends," he said. "And she did so in an attempt to save others."
Five other victims from Sandy Hook had services or calling hours scheduled on Friday.
Associated Press writers Matt Apuzzo in Washington and Pat Eaton-Robb in Newtown contributed to this report.
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