The 20 children were among 26 killed at Sandy Hook Elementary School in Newtown Dec. 14, just an hour from New York City. The gunman, Adam Lanza, 20, killed his mother, Nancy, as she slept, took four of the guns she so avidly collected, and broke into the school. When the shooting ended, he too was dead.
Among the weapons: a Bushmaster AR-15 rifle, the civilian version of the military's M-16. It was legally registered to Nancy Lanza, police said.
And the question of why remained by year's end.
Investigators hoping for clues in Lanza's computer were disappointed. Before embarking on his rampage, he destroyed the unit. As the investigation progressed, a picture emerged of a disturbed young man, who had spent the preceding days playing violent video games in the basement.
As the year came to a close, State Police Lt. Paul Vance said the investigation would be thorough -- and slow.
Father Peter Lanza and brother Ryan issued a statement through an attorney.
"Our family is grieving along with all those who have been affected by this enormous tragedy," the statement said in part. "We are in a state of disbelief and trying to find whatever answers we can. We too are asking why."
The two were in seclusion.
Speculation abounded. People who knew the family said he had mental issues. Some said Asperger's syndrome. Some said he was kind. Some said he shrank away from others, clutching a black briefcase to his chest in school hallways. Friends of Nancy's said she had found a residential school she thought would be good for her son in Washington state and planned to move there.
At first, there was confusion about the shooter's identity. He was carrying his older brother's identification.
But whether investigators ever are able to explain his motives, the sorrow remains. The Monday after the massacre, the town began burying its dead. They were ages 6 to 56. The first laid to rest were two young boys buried Monday. Then in twos, threes and more as the week wore on. By Dec. 22, the burials had been completed.
The dead children included: Charlotte Bacon, 6, Daniel Barden, 7, Olivia Engel, 6, Josephine Gay, 7, Ana M. Marquez-Greene, 6, Dylan Hockley, 6, Madeleine F. Hsu, 6, Catherine V. Hubbard, 6, Chase Kowalski, 7, Jesse Lewis, 6, James Mattioli, 6, Grace McDonnell, 7, Emilie Parker, 6, Jack Pinto, 6, Noah Pozner, 6, Caroline Previdi, 6, Jessica Rekos, 6, Avielle Richman, 6, Benjamin Wheeler, 6, and Allison N. Wyatt, 6. The adults killed were: Rachel Davino, 29, Dawn Hochsprung, 47, Anne Marie Murphy, 52, Lauren Rousseau, 30, Mary Sherlach, 56, and Victoria Soto, 27.
"You see little coffins and your heart has to ache," Gov. Dannel Malloy told The Hartford Courant at Noah's funeral.
The carnage capped a year of horrific attacks.
On July 20, a former University of Colorado doctoral student opened fire on a theater audience watching "The Dark Knight Rises," in Aurora, Colo., killing 12 people. The suspect was identified as James E. Holmes. At year's end, he was awaiting trial but his actions had yet to be explained.
In August, Wade Michael Page opened fire on priests and followers inside a Sikh temple in Oak Creek, Wis., killing six people. He was shot to death by police. In Brookfield, Wis., a man shot up a spa where his wife worked, killing her, two other women and then himself. In Portland, Ore., a masked gunman opened fire on a mall filled with Christmas shoppers, killing two people before killing himself.
The sheer number of incidents led President Obama to call for "meaningful action to prevent more tragedies like this, regardless of the politics."
The words were taken as a call for gun control. To erase any doubt, Obama followed up five days later by setting up a panel headed by Vice President Joe Biden "to come up with a set of concrete proposals no later than January -- proposals that I then intend to push without delay. This is not some Washington commission. This is not something where folks are going to be studying the issue for six months and publishing a report that gets read and then pushed aside. This is a team that has a very specific task, to pull together real reforms right now."
The president also said: "We may never know all the reasons why this tragedy happened. We do know that every day since, more Americans have died of gun violence. We know such violence has terrible consequences for our society. And if there is even one thing that we can do to prevent any of these events, we have a deep obligation -- all of us -- to try," adding, "The fact that this problem is complex can no longer be an excuse for doing nothing."
The National Rifle Association was muted in its response at first but then said the answer is more guns.
"The only thing that stops a bad guy with a gun is a good guy with a gun," NRA Chief Executive Officer Wayne LaPierre told a news conference a week after the massacre in calling for armed guards in every school to protect children.
In an appearance on "Meet the Press," LaPierre said the NRA would not support any gun control measures and doubled down on his call for armed guards.
"If it's crazy to call for putting police in and securing our schools to protect our children, then call me crazy," LaPierre said. "I think the American people think it's crazy not to do it. It's the one thing that would keep people safe and the NRA is going try to do that."
Sen. Tim Johnson of South Dakota, an NRA-backed Democrat, issued a statement saying the "tragedy will certainly force us as a country to have a discussion about our gun laws, as well as our mental health system."
Cerebus Capital Management, which owns Freedom Group, the company that makes the Bushmaster, said it planned to sell the gun's maker.
"It is apparent that the Sandy Hook tragedy was a watershed event that has raised the national debate on gun control to an unprecedented level," Cerebus said in a statement. "The debate essentially focuses on the balance between public safety and the scope of the Constitutional rights under the Second Amendment. As a firm, we are investors, not statesmen or policymakers."