Last December, 20-year-old Adam Lanza, 20, killed his mother, then 20 children and six staff members at Sandy Hook Elementary School in Connecticut before killing himself. The whole massacre took 5 minutes.
On Thursday, prosecutors released new documents related to the shooting. Here are the latest developments:
[Updated at 12:59 p.m. ET]
We've gotten all the documents together in one place. Here are the documents that Connecticut prosecutors released today in the Newtown investigation.
[Updated at 12:35 p.m. ET]
Back to today's Newtown document release. The National Rifle Association has issued a statement, apparently reacting to what the papers say about investigators finding NRA certificates for Lanza and his mother, Nancy.
"There is no record of a member relationship between Newtown killer Adam Lanza, nor between Nancy Lanza, A. Lanza or N. Lanza with the National Rifle Association," the NRA statement said. "Reporting to the contrary is reckless, false and defamatory."
[Updated at 12:17 p.m. ET]
President Obama's pro-gun-control event at the White House has just finished -- and he referred to Newtown many times as he tried to fight against waning public support for Senate Democrats' post-Newtown gun-control proposals.
He essentially was arguing that some people are suffering from short attention spans -- that people who were persuaded to support ammunition magazine limits and universal background checks immediately after the Newtown shootings might be letting their support slip because Newtown is no longer in the news every day.
"We need everybody to remember how they felt 100 days ago (after the Newtown shooting) and make sure (what we said then) wasn't just a bunch of platitudes," Obama said.
"Now's the time to turn that heartbreak into something real."
Obama also said that "some powerful voices on the other side" want to delay action on gun legislation. "Their assumption is that people will just forget about it," the president said.
Earlier this month, NRA executive vice president Wayne LaPierre said background checks of firearms purchases won't stop gun violence, but would serve agendas of people "bent on destroying the Second Amendment." In a speech to the Conservative Political Action Conference, he said expanded background checks would be a first step toward a liberal desire to create a national gun registry.
"In the end, there are only two reasons for government to create that federal registry of gun owners -- to tax them or to take them," LaPierre said on March 15. Supporters of expanded checks deny the legislation would create such a registry.
[Updated at 12:07 p.m. ET]
President Obama, at his pro-gun-control event at the White House, says the anguish is still fresh in Newtown, and that thousands of Americans' lives have been "stolen by bullets" in recent months.
Some background on the legislation that Obama is backing: Proposed by Senate Democrats, the package includes expanded background checks, tougher laws against gun trafficking and straw purchases, and efforts to improve school security.
He said moments ago: "This is our best chance in more than a decade" to pass what Obama believes is "common-sense gun control legislation."
Obama recalls that when he visited Newtown after the shooting, he told people there that if there's a step that Washington can take to save just one child, Washington should do it.
"None of these ideas should be controversial," Obama says.
Recent polls show support for new gun legislation on the wane, and Obama appears to be reacting to that.
"Shame on us if we've forgotten" the horrors of Newtown, Obama said. "I haven't forgotten those kids."
[Updated at 11:58 a.m. ET]
President Obama's pro-gun-control event at the White House has begun. We're listening to see if he mentions Newtown.